Understanding and mitigating security risks in MCP implementations
Introducing any new technology can introduce new security challenges or exacerbate existing security risks. In this blog post, we’re going to look at some of the security risks that could be introduced to your environment when using Model Context Protocol (MCP), and what controls you can put in place to mitigate them. MCP is a framework that enables seamless integration between LLM applications and various tools and data sources. MCP defines: A standardized way for AI models to request external actions through a consistent API Structured formats for how data should be passed to and from AI systems Protocols for how AI requests are processed, executed, and returned MCP allows different AI systems to use a common set of tools and patterns, ensuring consistent behavior when AI models interact with external systems. MCP architecture MCP follows a client-server architecture that allows AI models to interact with external tools efficiently. Here’s how it works: MCP Host – The AI model (e.g., Azure OpenAI GPT) requesting data or actions. MCP Client – An intermediary service that forwards the AI model's requests to MCP servers. MCP Server – Lightweight applications that expose specific capabilities (APIs, databases, files, etc.). Data Sources – Various backend systems, including local storage, cloud databases, and external APIs. MCP security controls Any system which has access to important resources has implied security challenges. Security challenges can generally be addressed through correct application of fundamental security controls and concepts. As MCP is only newly defined, the specification is changing very rapidly and as the protocol evolves. Eventually the security controls within it will mature, enabling a better integration with enterprise and established security architectures and best practices. Research published in the Microsoft Digital Defense Report states that 98% of reported breaches would be prevented by robust security hygiene and the best protection against any kind of breach is to get your baseline security hygiene, secure coding best practices and supply chain security right – those tried and tested practices that we already know about still make the most impact in reducing security risk. Let's look at some of the ways that you can start to address security risks when adopting MCP. MCP server authentication (if your MCP implementation was before 26th April 2025) Problem statement: The original MCP specification assumed that developers would write their own authentication server. This requires knowledge of OAuth and related security constraints. MCP servers acted as OAuth 2.0 Authorization Servers, managing the required user authentication directly rather than delegating it to an external service such as Microsoft Entra ID. As of 26 April 2025, an update to the MCP specification allows for MCP servers to delegate user authentication to an external service. Risks: Misconfigured authorization logic in the MCP server can lead to sensitive data exposure and incorrectly applied access controls. OAuth token theft on the local MCP server. If stolen, the token can then be used to impersonate the MCP server and access resources and data from the service that the OAuth token is for. Mitigating controls: Thoroughly review your MCP server authorization logic, here some posts discussing this in more detail - Azure API Management Your Auth Gateway For MCP Servers | Microsoft Community Hub and Using Microsoft Entra ID To Authenticate With MCP Servers Via Sessions · Den Delimarsky Implement best practices for token validation and lifetime Use secure token storage and encrypt tokens Excessive permissions for MCP servers Problem statement: MCP servers may have been granted excessive permissions to the service/resource they are accessing. For example, an MCP server that is part of an AI sales application connecting to an enterprise data store should have access scoped to the sales data and not allowed to access all the files in the store. Referencing back to the principle of least privilege (one of the oldest security principles), no resource should have permissions in excess of what is required for it to execute the tasks it was intended for. AI presents an increased challenge in this space because to enable it to be flexible, it can be challenging to define the exact permissions required. Risks: Granting excessive permissions can allow for exfiltration or amending data that the MCP server was not intended to be able to access. This could also be a privacy issue if the data is personally identifiable information (PII). Mitigating controls: Clearly define the permissions that the MCP server has to access the resource/service it connects to. These permissions should be the minimum required for the MCP server to access the tool or data it is connecting to. Indirect prompt injection attacks Problem statement: Researchers have shown that the Model Context Protocol (MCP) is vulnerable to a subset of Indirect Prompt Injection attacks known as Tool Poisoning Attacks. Tool poisoning is a scenario where an attacker embeds malicious instructions within the descriptions of MCP tools. These instructions are invisible to users but can be interpreted by the AI model and its underlying systems, leading to unintended actions that could ultimately lead to harmful outcomes. Risks: Unintended AI actions present a variety of security risks that include data exfiltration and privacy breaches. Mitigating controls: Implement AI prompt shields: in Azure AI Foundry, you can follow these steps to implement AI prompt shields. Implement robust supply chain security: you can read more about how Microsoft implements supply chain security internally here. Established security best practices that will uplift your MCP implementation’s security posture Any MCP implementation inherits the existing security posture of your organization's environment that it is built upon, so when considering the security of MCP as a component of your overall AI systems it is recommended that you look at uplifting your overall existing security posture. The following established security controls are especially pertinent: Secure coding best practices in your AI application - protect against the OWASP Top 10, the OWASP Top 10 for LLMs, use of secure vaults for secrets and tokens, implementing end-to-end secure communications between all application components, etc. Server hardening – use MFA where possible, keep patching up to date, integrate the server with a third party identity provider for access, etc. Keep devices, infrastructure and applications up to date with patches Security monitoring – implementing logging and monitoring of an AI application (including the MCP client/servers) and sending those logs to a central SIEM for detection of anomalous activities Zero trust architecture – isolating components via network and identity controls in a logical manner to minimize lateral movement if an AI application were compromised. Conclusion MCP is a promising development in the AI space that enables rich data and context access. As developers embrace this new approach to integrating their organization's APIs and connectors into LLMs, they need to be aware of security risks and how to implement controls to reduce those risks. There are mitigating security controls that can be put in place to reduce the risks inherent in the current specification, but as the protocol develops expect that some of the risks will reduce or disappear entirely. We encourage you to contribute to and suggest security related MCP RFCs to make this protocol even better! With thanks to OrinThomas, dasithwijes, dendeli and Peter Marcu for their inputs and collaboration on this post.Graph RAG for Security: Insights from a Microsoft Intern
As a software engineering intern at Microsoft Security, I had the exciting opportunity to explore how Graph Retrieval-Augmented Generation (Graph RAG) can enhance data security investigations. This blog post shares my learning journey and insights from working with this evolving technology.Step by Step: 2-Tier PKI Lab
Purpose of this blog Public Key Infrastructure (PKI) is the backbone of secure digital identity management, enabling encryption, digital signatures, and certificate-based authentication. However, neither setting up a PKI nor management of certificates is something most IT pros do on a regular basis and given the complexity and vastness of the subject it only makes sense to revisit the topic from time to time. What I have found works best for me is to just set up a lab and get my hands dirty with the topic that I want to revisit. One such topic that I keep coming back to is PKI - be it for creating certificate templates, enrolling clients, or flat out creating a new PKI itself. But every time I start deploying a lab or start planning a PKI setup, I end up spending too much time sifting through the documentations and trying to figure out why my issuing certificate authority won't come online! To make my life easier I decided to create a cheatsheet to deploy a simple but secure 2-tier PKI lab based on industry best practices that I thought would be beneficial for others like me, so I decided to polish it and make it into a blog. This blog walks through deploying a two-tier PKI hierarchy using Active Directory Certificate Services (AD CS) on Windows Server: an offline Root Certification Authority (Root CA) and an online Issuing Certification Authority (Issuing CA). We’ll cover step-by-step deployment and best practices for securing the root CA, conducting key ceremonies, and maintaining Certificate Revocation Lists (CRLs). Overview: Two-Tier PKI Architecture and Components In a two-tier PKI, the Root CA sits at the top of the trust hierarchy and issues a certificate only to the subordinate Issuing CA. The Root CA is kept offline (disconnected from networks) to protect its private key and is typically a standalone CA (not domain-joined). The Issuing CA (sometimes called a subordinate or intermediate CA) is kept online to issue certificates to end-entities (users, computers, services) and is usually an enterprise CA integrated with Active Directory for automation and certificate template support. Key components: Offline Root CA: A standalone CA, often on a workgroup server, powered on only when necessary (initial setup, subordinate CA certificate signing, or periodic CRL publishing). By staying offline, it is insulated from network threats. Its self-signed certificate serves as the trust anchor for the entire PKI. The Root CA’s private key must be rigorously protected (ideally by a Hardware Security Module) because if the root is compromised, all certificates in the hierarchy are compromised. Online Issuing CA: An enterprise subordinate CA (domain-joined) that handles day-to-day certificate issuance for the organization. It trusts the Root CA (via the root’s certificate) and is the one actually responding to certificate requests. Being online, it must also be secured, but its key is kept online for operations. Typically, the Issuing CA publishes certificates and CRLs to Active Directory and/or HTTP locations for clients to download. The following diagram shows the simplified view of this implementations: The table below summarizes the roles and differences: Aspect Offline Root CA Online Issuing CA Role Standalone Root CA (workgroup) Enterprise Subordinate CA (domain member) Network Connectivity Kept offline (powered off or disconnected when not issuing) Online (running continuously to serve requests) Usage Signs only one certificate (the subordinate CA’s cert) and CRLs Issues end-entity certificates (users, computers, services) Active Directory Not a member of AD domain; doesn’t use templates or auto-enrollment Integrated with AD DS; uses certificate templates for streamlined issuance Security Extremely high: physically secured, limited access, often protected by HSM Very High: server hardened, but accessible on network; HSM recommended for private key CRL Publication Manual. Admin must periodically connect, generate, and distribute CRL. Delta CRLs usually disabled. Automatic. Publishes CRLs to configured CDP locations (AD DS, HTTP) at scheduled intervals. Validity Period Longer (e.g. 5-10+ years for the CA certificate) to reduce frequency of renewal. Shorter (e.g. 2 years) to align with organizational policy; renewed under the root when needed. In this lab setup, we will create a Contoso Root CA (offline) and a Contoso Issuing CA (online) as an example. This mirrors real-world best practices which is to "deploy a standalone offline root CA and an online enterprise subordinate CA”. Deploying the Offline Root CA Setting up the offline Root CA involves preparing a dedicated server, installing AD CS, configuring it as a root CA, and then securing it. We’ll also configure certificate CDP/AIA (CRL Distribution Point and Authority Information Access) locations so that issued certificates will point clients to the correct locations to fetch the CA’s certificate and revocation list. Step 1: Prepare the Root CA Server (Offline) Provision an isolated server: Install a Windows Server OS (e.g., Windows Server 2022) on the machine designated to be the Root CA. Preferably on a portable enterprise grade physical server that can be stored in a safe. Do not join this server to any domain – it should function in a Workgroup to remain independent of your AD forest. System configuration: Give the server a descriptive name (e.g., ROOTCA) and assign a static IP (even though it will be offline, a static IP helps when connecting it temporarily for management). Install the latest updates and security patches while it’s still able to go online. Lock down network access: Once setup is complete, disable or unplug network connections. If the server must remain powered on for any reason, ensure all unnecessary services/ports are disabled to minimize exposure. In practice, you will keep this server shut down or physically disconnected except when performing CA maintenance. Step 2: Install the AD CS Role on the Root CA Add the Certification Authority role: On the Root CA server, open Server Manager and add the Active Directory Certificate Services role. During the wizard, select the Certification Authority role service (no need for web enrollment or others on the root). Proceed through the wizard and complete the installation. You can also install the CA role and management tools via PowerShell: Install-WindowsFeature AD-Certificate -IncludeManagementToolsThis Role Services: Choose Certification Authority. Setup Type: Select Standalone CA (since this root CA is not domain-joined). CA Type: Select Root CA. Private Key: Choose “Create a new private key.” Cryptography: If using an HSM, select the HSM’s Cryptographic Service Provider (CSP) here; otherwise use default. Choose a strong key length (e.g., 2048 or 4096 bits) and a secure hash algorithm (SHA-256 or higher). CA Name: Provide a common name for the CA (e.g., “Contoso Root CA”). This name will appear in issued certificates as the Issuer. Avoid using a machine DNS name here for security – pick a name without revealing the server’s actual hostname. Validity Period: Set a long validity (e.g., 10 years) for the root CA’s self-signed certificate. A decade is common for enterprise roots, reducing how often you must touch the offline CA for renewal. Database: Specify locations for the CA database and logs (the defaults are fine for a lab). Review settings and complete the configuration. This process will generate the root CA’s key pair and self-signed certificate, establishing the Root CA.Post-install configuration: After the binary installation, click Configure Active Directory Certificate Services (a notification in Server Manager). In the configuration wizard: You can also perform this configuration via PowerShell in one line: Install-AdcsCertificationAuthority ` -CAType StandaloneRootCA ` -CryptoProviderName "YourHSMProvider" ` -HashAlgorithmName SHA256 -KeyLength 2048 ` -CACommonName "Contoso Root CA" ` -ValidityPeriod Years -ValidityPeriodUnits 10 This would set up a standalone Root CA named "Contoso Root CA" with a 2048-bit key on an HSM provider, valid for 10 years. Step 3: Integrate an HSM (Optional but Recommended) If your lab has a Hardware Security Module, use it to secure the Root CA’s keys. Using an HSM provides a dedicated, tamper-resistant storage for CA private keys and can further protect against key compromise. To integrate: Install the HSM vendor’s software and drivers on the Root CA server. Initialize the HSM and create a security world or partition as per the vendor instructions. Before or during the CA configuration (Step 2 above), ensure the HSM is ready to generate/store the key. When running the AD CS configuration, select the HSM’s CSP/KSP for the cryptographic provider so that the CA’s private key is generated on the HSM. Secure any HSM admin tokens or smartcards. For a root CA, you might employ M of N key splits – requiring multiple key custodians to collaborate to activate the HSM or key – as part of the key ceremony (discussed later). (If an HSM is not available, the root key will be stored on the server’s disk. At minimum, protect it with a strong admin passphrase when prompted, and consider enabling the option to require administrator interaction (e.g., a password) whenever the key is accessed.) Step 4: Configure CA Extensions (CDP/AIA) It’s critical to configure how the Root CA publishes its certificate and revocation list, since the root is offline and cannot use Active Directory auto-publishing. Open the Certification Authority management console (certsrv.msc), right-click the CA name > Properties, and go to the Extensions tab. We will set the CRL Distribution Points (CDP) and Authority Information Access (AIA) URLs: CRL Distribution Point (CDP): This is where certificates will tell clients to fetch the CRL for the Root CA. By default, a standalone CA might have a file:// path or no HTTP URL. Click Add and specify an HTTP URL that will be accessible to all network clients, such as: http://<IssuingCA_Server>/CertEnroll/<CaName><CRLNameSuffix><DeltaCRLAllowed>.crl For example, if your issuing CA’s server name is ISSUINGCA.contoso.local, the URL might be http://issuingca.contoso.local/CertEnroll/Contoso%20Root%20CA.crl This assumes the Issuing CA (or another web server) will host the Root CA’s CRL in the CertEnroll directory. Check the boxes for “Include in the CDP extension of issued certificates” and “Include in all CRLs. Clients use this to find Delta CRLs” (you can uncheck the delta CRL publication on the root, as we won’t use delta CRLs on an offline root). Since the root CA won’t often revoke its single issued cert (the subordinate CA), delta CRLs aren’t necessary. Note: If your Active Directory is in use and you want to publish the Root CA’s CRL to AD, you can also add an ldap:///CN=... path and check “Publish in Active Directory”. However, publishing to AD from an offline CA must be done manually using the following command when the root is temporarily connected. certutil -dspublish Many setups skip LDAP for offline roots and rely on HTTP distribution. Authority Information Access (AIA): This is where the Root CA’s certificate will be published for clients to download (to build certificate chains). Add an HTTP URL similarly, for example: http://<IssuingCA_Server>/CertEnroll/<ServerDNSName>_<CaName><CertificateName>.crt This would point to a copy of the Root CA’s certificate that will be hosted on the issuing CA web server. Check “Include in the AIA extension of issued certificates”. This way, any certificate signed by the Root CA (like your subordinate CA’s cert) contains a URL where clients can fetch the Root CA’s cert if they don’t already have it. After adding these, remove any default entries that are not applicable (e.g., LDAP if the root isn’t going to publish to AD, or file paths that won’t be used by clients). These settings ensure that certificates issued by the Root CA (in practice, just the subordinate CA’s certificate) will carry the correct URLs for chain building and revocation checking. Step 5: Back Up the Root CA and Issue the Subordinate Certificate With the Root CA configured, we need to issue a certificate for the Issuing CA (subordinate). We’ll perform that in the next section from the Issuing CA’s side via a request file. Before taking the root offline, ensure you: Back up the CA’s private key and certificate: In the Certification Authority console, or via the CA Backup wizard, export the Root CA’s key pair and CA certificate. Protect this backup (store it offline in a secure location, e.g., on encrypted removable media in a safe). This backup is crucial for disaster recovery or if the Root CA needs to be migrated or restored. Save the Root CA Certificate: You will need the Root CA’s public certificate (*.crt) to distribute to other systems. Have it exported (Base-64 or DER format) for use on the Issuing CA and for clients. Initial CRL publication: Manually publish the first CRL so that it can be distributed. Open an elevated Command Prompt on the Root CA and run: certutil -crl This generates a new CRL file (in the CA’s configured CRL folder, typically %windir%\system32\CertSrv\CertEnroll). Take that CRL file and copy it to the designated distribution point (for example, to the CertEnroll directory on the Issuing CA’s web server, as per the HTTP URL configured). If using Active Directory for CRL distribution, you would also publish it to AD now (e.g., certutil -dspublish -f RootCA.crl on a domain-connected machine). In most lab setups, copying to an HTTP share is sufficient. With these tasks done, the Root CA is ready. At this point, disconnect or power off the Root CA and store it securely – it should remain offline except when it’s absolutely needed (like publishing a new CRL or renewing the subordinate CA’s certificate in the far future). Keeping the root CA offline maximizes its security by minimizing exposure to compromise. Best Practices for Securing the Root CA: The Root CA is the trust anchor, so apply stringent security practices: Physical security: Store the Root CA machine in a locked, secure location. If it’s a virtual machine, consider storing it on a disconnected hypervisor or a USB drive locked in a safe. Only authorized PKI team members should have access. An offline CA should be treated like crown jewels – offline CAs should be stored in secure locations. Minimal exposure: Keep the Root CA powered off and disconnected when not in use. It should not be left running or connected to any network. Routine operations (like issuing end-entity certs) should never involve the root. Admin access control: Limit administrative access on the Root CA server. Use dedicated accounts for PKI administration. Enable auditing on the CA for any changes or issuance events. No additional roles or software: Do not use the Root CA server for any other function (no web browsing, no email, etc.). Fewer installed components means fewer potential vulnerabilities. Protect the private key: Use an HSM if possible; if not, ensure the key is at least protected by a strong password and consider splitting knowledge of that password among multiple people (so no single person can activate the CA). Many organizations opt for an offline root key ceremony (see below) to generate and handle the root key with multiple witnesses and strict procedures. Keep system time and settings consistent: If the Root CA is powered off for long periods, ensure its clock is accurate whenever it is started (to avoid issuing a CRL or certificate with a wrong date). Don’t change the server name or CA name after installation (doing so invalidates issued certs). Periodic health checks: Even though offline, plan to turn on the Root CA at a secure interval (e.g., semi-annually or annually) to perform tasks like CRL publishing and system updates. Make sure to apply OS security updates during these maintenance windows, as offline does not mean immune to vulnerabilities (especially if it ever connects to a network for CRL publication or uses removable media). Deploying the Online Issuing CA Next, set up the Issuing CA server which will actually issue certificates to end entities in the lab. This server will be domain-joined (if using AD integration) and will obtain its CA certificate from the Root CA we just configured. Step 1: Prepare the Issuing CA Server Provision the server: Install Windows Server on a new machine (or VM) that will be the Issuing CA. Join this server to the Active Directory domain (e.g., Contoso.local). Being an enterprise CA, it needs domain membership to publish templates and integrate with AD security groups. Rename the server to something descriptive like ISSUINGCA for clarity. Assign a static IP and ensure it can communicate on the network. IIS for web enrollment (optional): If you plan to use the Web Enrollment or Certificate Enrollment Web Services, ensure IIS is installed. (The AD CS installation wizard can add it if you include those role services.) For this guide, we will include the Web Enrollment role so that the CertEnroll directory is set up for hosting certificate and CRL files. Step 2: Install AD CS Role on Issuing CA On the Issuing CA server, add the Active Directory Certificate Services role via Server Manager or PowerShell. This time, select both Certification Authority and Certification Authority Web Enrollment role services (Web Enrollment will set up the HTTP endpoints for certificate requests if needed). For example, using PowerShell: Install-WindowsFeature AD-Certificate, ADCS-Web-Enrollment -IncludeManagementTools After installation, launch the AD CS configuration wizard: Role Services: Choose Certification Authority (and Web Enrollment if prompted). Setup Type: Select Enterprise CA (since this CA will integrate with AD DS). CA Type: Select Subordinate CA (this indicates it will get its cert from an existing root CA). Private Key: Choose “Create a new private key” (we’ll generate a new key pair for this CA). Cryptography: If using an HSM here as well, select the HSM’s CSP/KSP for the issuing CA’s key. Otherwise, choose a strong key length (2048+ bits, SHA256 or better for hash). CA Name: Provide a name (e.g., “Contoso Issuing CA”). This name will appear as the Issuer on certificates it issues. Certificate Request: The wizard will ask how you want to get the subordinate CA’s certificate. Choose “Save a certificate request to file”. Specify a path, e.g., C:\CertRequest\issuingCA.req. The wizard will generate a request file that we need to take to the Root CA for signing. (Since our Root CA is offline, this file transfer might be via secure USB or a network share when the root is temporarily online.) CA Database: Choose locations or accept defaults for the certificate DB and logs. Finish the configuration wizard, which will complete pending because the CA doesn’t have a certificate yet. The AD CS service on this server won’t start until we import the issued cert from the root. Step 3: Integrate HSM on Issuing CA (Optional) If available, repeat the HSM setup on the Issuing CA: install HSM drivers, initialize it, and generate/secure the key for the subordinate CA on the HSM. Ensure you chose the HSM provider during the above configuration so that the issuing CA’s private key is stored in the HSM. Even though this CA is online, an HSM still greatly enhances security by protecting the private key from extraction. The issuing CA’s HSM may not require multiple custodians to activate (as it needs to run continuously), but should still be physically secured. Step 4: Obtain the Issuing CA’s Certificate from the Root CA Now we have a pending request (issuingCA.req) for the subordinate CA. To get its certificate: Transport the request to the Root CA: Copy the request file to the offline Root CA (via secure means – e.g., formatted new USB stick). Start up the Root CA (in a secure, offline setting) and open the Certification Authority console. Submit the request on Root CA: Right-click the Root CA in the CA console -> All Tasks -> Submit new request, and select the .req file. The request will appear in the Pending Requests on the root. Issue the subordinate CA certificate: Find the pending request (it will list the Issuing CA’s name). Right-click and choose All Tasks > Issue. The subordinate CA’s certificate is now issued by the Root CA. Export the issued certificate: Still on the Root CA, go to Issued Certificates, find the newly issued subordinate CA cert (you can identify it by the Request ID or by the name). Right-click it and choose Open or All Tasks > Export to get the certificate in a file form. If using the console’s built-in “Export” it might only allow binary; alternatively use the certutil command: certutil -dup <RequestID> .\ContosoIssuingCA.cer or simply open and copy to file. Save the certificate as issuingCA.cer. Also make sure you have a copy of the Root CA’s certificate (if not already done). Publish Root CA cert and CRL as needed: Before leaving the Root CA, you may also want to ensure the Root’s own certificate and latest CRL are available to the issuing CA and clients. If not already done in Step 5 of root deployment, export the Root CA cert (DER format) and copy the CRL file. You might use certutil -crl again if some time has passed since initial CRL. Now take the issuingCA.cer file (and root cert/CRL files) and move them back to the Issuing CA server. Step 5: Install the Issuing CA’s Certificate and Complete Configuration On the Issuing CA server (which is still waiting for its CA cert): Install the subordinate CA certificate: In Server Manager or the Certification Authority console on the Issuing CA, there should be an option to “Install CA Certificate” (if the AD CS configuration wizard is still open, it will prompt for the file; or otherwise, in the CA console right-click the CA name > All Tasks > Install CA Certificate). Provide the issuingCA.cer file obtained from the root. This will install the CA’s own certificate and start the CA service. The Issuing CA is now operational as a subordinate CA. Alternatively, use PowerShell: certutil -installcert C:\CertRequest\issuingCA.cer This installs the cert and associates it with the pending key. Trust the Root CA certificate: Because the Issuing CA is domain-joined, when you install the subordinate cert, it might automatically place the Root CA’s certificate in the Trusted Root Certification Authorities store on that server (and possibly publish it to AD). If not, you should manually install the Root CA’s certificate into the Trusted Root CA store on the Issuing CA machine (using the Certificates MMC or certutil -addstore -f Root rootCA.cer). This step prevents any “chain not trusted” warnings on the Issuing CA and ensures it trusts its parent. In an enterprise environment, you would also distribute the root certificate to all client machines (e.g., via Group Policy) so that they trust the whole chain. Import Root CRL: Copy the Root CA’s CRL (*.crl file) to the Issuing CA’s CRL distribution point location (e.g., C:\Windows\System32\CertSrv\CertEnroll\ if that’s the directory served by the web server). This matches the HTTP URL we configured on the root. Place the CRL file there and ensure it is accessible (the Issuing CA’s IIS might need to serve static .crl files; often, if Web Enrollment is installed, the CertEnroll folder is under C:\Inetpub\wwwroot\CertEnroll). At this point, the subordinate CA and any client hitting the HTTP URL can retrieve the root’s CRL. The subordinate CA is now fully established. It holds a certificate issued by the Root CA (forming a complete chain of trust), and it’s ready to issue end-entity certificates. Step 6: Configure Issuing CA Settings and Start Services Start the Certificate Services: If the CA service (CertSvc) isn’t started automatically, start or restart it. On PowerShell: Restart-Service certsvc The CA should show as running in the CA console with the name “Contoso Issuing CA” (or your chosen name). Configure Certificate Templates: Because this is an Enterprise CA, it can utilize certificate templates stored in Active Directory to simplify issuing common cert types (user auth, computer auth, web server SSL, etc.). By default, some templates (e.g., User, Computer) are available but not issued. In the Certification Authority console under Certificate Templates, you can choose which templates to issue (e.g., right-click > New > Certificate Template to Issue, then select templates like “User” or “Computer”). This lab guide doesn’t require specific templates but know that only Enterprise CAs can use templates. Templates define the policies and settings (cryptography, enrollment permissions, etc.) for issued certificates. Ensure you enable only the templates needed and configure their permissions appropriately (e.g., allow the appropriate groups to enroll). Set CRL publishing schedule: The Issuing CA will automatically publish its own CRL (for certificates it issues) at intervals. You can adjust the CRL and Delta CRL publication interval in the CA’s Properties > CRL Period. A common practice is a small base CRL period (e.g., 1 week or 2 weeks) for issuing CAs, because they may revoke user certs more frequently; and enable Delta CRLs (published daily) for timely revocation information. Make sure the CDP/AIA for the Issuing CA itself are properly configured too (the wizard usually sets LDAP and HTTP locations, but verify in the Extensions tab). In a lab, the default settings are fine. Web Enrollment (if installed): You can verify the web enrollment by browsing to http://<IssuingCA>/certsrv. This web UI allows browser-based certificate requests. It’s a legacy interface mostly, but for testing it can be used if your clients aren’t domain-joined or if you want a manual request method. In modern use, the Certificate Enrollment Web Service/Policy roles or auto-enrollment via Group Policy are preferred for remote and automated enrollment. At this stage, your PKI is operational: the Issuing CA trusts the offline Root CA and can issue certificates. The Root CA can be kept offline with confidence that the subordinate will handle all regular work. Validation and Testing of the PKI It’s important to verify that the PKI is configured correctly: Check CA status: On the Issuing CA, open the Certification Authority console and ensure no errors. Verify that the Issuing CA’s certificate shows OK (no red X). On the Root CA (offline most of the time), you can use the Pkiview.msc snap-in (Microsoft PKI Health Tool) on a domain-connected machine to check the health of the PKI. This tool will show if the CDPs/AIA are reachable and if certificates are properly published. Trust chain on clients: On a domain-joined client PC, the Root CA certificate should be present in the Trusted Root Certification Authorities store (if the Issuing CA was installed as Enterprise CA, it likely published the root cert to AD automatically; you can also distribute it via Group Policy or manually). The Issuing CA’s certificate should appear in the Intermediate Certification Authorities store. This establishes the chain of trust. If not, import the root cert into the domain’s Group Policy for Trusted Roots. A quick test: on a client, run certutil -config "ISSUINGCA\\Contoso Issuing CA" -ping to see if it can contact the CA (or use the Certification Authority MMC targeting the issuing CA). Enroll a test certificate: Try to enroll for a certificate from the Issuing CA. For instance, from a domain-joined client, use the Certificates MMC (in Current User or Computer context) and initiate a certificate request for a User or Computer certificate (depending on templates issued). If auto-enrollment is configured via Group Policy for a template, you can simply log on a client and see if it automatically receives a certificate. Alternatively, use the web enrollment page or certreq command to submit a request. The request should be approved and a certificate issued by "Contoso Issuing CA". After enrollment, inspect the issued certificate: it should chain up to "Contoso Root CA" without errors. Ensure that the certificate’s CDP points to the URL we set (and try to browse that URL to see the CRL file), and that the AIA points to the root cert location. Revocation test (optional): To test CRL behavior, you could revoke a test certificate on the Issuing CA (using the CA console) and publish a new CRL. On the client, after updating the CRL, the revoked certificate should show as revoked. For the Root CA, since it shouldn’t issue end-entity certs, you wouldn’t normally revoke anything except potentially the subordinate CA’s certificate (which would be a drastic action in case of compromise). By issuing a test certificate and validating the chain and revocation, you confirm that your two-tier PKI lab is functioning correctly. Maintaining the PKI: CRLs, Key Ceremonies, and Security Procedures Deploying the PKI is only the beginning. Proper maintenance and operational procedures are crucial to ensure the PKI remains secure and reliable over time. Periodic CRL Updates for the Offline Root: The Root CA’s CRL has a defined validity period (set during configuration, often 6 or 12 months for offline roots). Before the CRL expires, the Root CA must be brought online (in a secure environment) to issue a new CRL. It’s recommended to schedule CRL updates periodically (e.g., semi-annually) to prevent the CRL from expiring. An expired CRL can cause certificate chain validation to fail, potentially disrupting services. Typically, organizations set the offline root CRL validity so that publishing 1-2 times a year is sufficient. When the time comes: Start the Root CA (ensuring the system clock is correct). Run certutil -crl to issue a fresh CRL. Distribute the new CRL: copy it to the HTTP CDP location (overwrite the old file) and, if applicable, use certutil -dspublish -f RootCA.crl to update it in Active Directory. Verify that the new CRL’s next update date is extended appropriately (e.g., another 6 months out). Clients and the Issuing CA will automatically pick up the new CRL when checking for revocation. (The Issuing CA, if configured, might cache the root CRL and need a restart or certutil -setreg ca\CRLFlags +CRLF_REVCHECK_IGNORE_OFFLINE tweak if the root CRL expires unexpectedly. Keeping the schedule prevents such issues.) Issuing CA CRL and OCSP: The Issuing CA’s CRLs are published automatically as it is online. Ensure the IIS or file share hosting the CRL is accessible. Optionally, consider setting up an Online Responder (OCSP) for real-time status checking, especially if CRLs are large or you need faster revocation information. OCSP is another AD CS role service that can be configured on the issuing CA or another server to answer certificate status queries. This might be beyond a simple lab, but it’s worth mentioning for completeness. Key Ceremonies and Documentation: For production environments (and good practice even in labs), formalize the process of handling CA keys in a Key Ceremony. A key ceremony is a carefully controlled process for activities like generating the Root CA’s key pair, installing the CA, and signing subordinate certificates. It often involves multiple people to ensure no single person has unilateral control (principle of dual control) and to witness the process. Best practices for a Root CA key ceremony include: Advance Planning: Create a step-by-step script of the ceremony tasks. Include who will do what, what materials are needed (HSMs, installation media, backup devices, etc.), and the order of operations. Multiple trusted individuals present: Roles might include a Ceremony Administrator (leads the process), a Security Officer (responsible for HSM or key material handling), an Auditor (to observe and record), etc. This prevents any one person from manipulating the process and increases trust. Secure environment: Conduct the ceremony in a secure location (e.g., a locked room) free of recording devices or unauthorized personnel. Ensure the Root CA machine is isolated (no network), and ideally that BIOS/USB access controls are in place to prevent any malware. Generate keys with proper controls: If using an HSM, initialize and generate the key with the required number of key custodians each providing part of the activation material (e.g., smartcards or passphrases). Immediately back up the HSM partition or key to secure media (requiring the same custodians to restore). Sign subordinate CA certificate: As part of the ceremony, once the root key is ready, sign the subordinate’s request. This might also be a witnessed step. Document every action: Write down each command run, each key generated, serial numbers of devices used, and have all participants sign an acknowledgment of the outcomes. Also record the fingerprints of the generated Root CA certificate and any subordinate certificate to ensure they are exactly as expected. Secure storage: After the ceremony, store the Root CA machine (if it’s a laptop or VM) and HSM tokens in a tamper-evident bag or safe. The idea is to make it evident if someone tries to access the root outside of an authorized ceremony. While a full key ceremony might be overkill for a small lab, understanding these practices is important. Even in a lab, you can simulate some aspects (for learning), like documenting the procedure of taking the root online to sign the request and then locking it away. These practices greatly increase the trust in a production PKI by ensuring transparency and accountability for critical operations. Backup and Recovery Plans: Both CAs’ data should be regularly backed up: For the Root CA: since it’s rarely online, backup after any change. Typically, you’d back up the CA’s private key and certificate once (right after setup or any renewal). Store this securely offline (separate from the server itself). Also back up the CA database if it ever issues more than one cert (for root it might not issue many). For the Issuing CA: schedule automated backups of the CA database and private key. You can use the built-in certutil -backup or Windows Server Backup (which is aware of the AD CS database). Keep backups secure and test restoration procedures. Having a documented recovery procedure for the CA is crucial for continuity. Also consider backup of templates and any scripts. Maintain spare hardware or VMs in case you need to restore the CA on new hardware (especially for the root, having a procedure to restore on a new machine if the original is destroyed). Security maintenance: Apply OS updates to the CAs carefully. For the offline root, patch it offline if possible (offline servicing or connecting it briefly to a management network). For the issuing CA, treat it as a critical infrastructure server: limit its exposure (firewall it so only required services are reachable), monitor its event logs (enable auditing for Certificate Services events, which can log each issuance and revocation), and employ anti-malware tools with caution (whitelisting the CA processes to avoid interference). Also, periodically review the CA’s configuration and certificate templates to ensure they meet current security standards (for example, deprecate any weak cryptography or adjust validity periods if needed). By following these maintenance steps and best practices, your two-tier PKI will remain secure and trustworthy over time. Remember that PKI is not “set and forget” – it requires operational diligence, but the payoff is a robust trust infrastructure for your organization’s security. Additional AD CS Features and References Active Directory Certificate Services provides more capabilities than covered in this basic lab. Depending on your needs, you might explore: Certificate Templates: We touched on templates; they are a powerful feature on Enterprise CAs to enforce standardized certificate settings. Administrators can create custom templates for various use cases (SSL, S/MIME email, code signing) and control enrollment permissions. Understanding template versions and permissions is key for enterprise deployments. (Refer to Microsoft’s documentation on Certificate template concepts in Windows Server for details on how templates work and can be customized.) Web Services for Enrollment: In scenarios with remote or non-domain clients, AD CS offers the Certificate Enrollment Web Service (CES) and Certificate Enrollment Policy Web Service (CEP) role services. These allow clients to fetch enrollment policy information and request certificates over HTTP or HTTPS, even when not connected directly to the domain. They work with the certificate templates to enable similar auto-enrollment experiences over the web. See Microsoft’s guides on the Certificate Enrollment Web Service overview and Certificate Enrollment Policy Web Service overview for when to use these. Network Device Enrollment Service (NDES): This AD CS role service implements the Simple Certificate Enrollment Protocol (SCEP) to allow devices like routers, switches, and mobile devices to obtain certificates from the CA without domain credentials. NDES acts as a proxy (Registration Authority) between devices and the CA, using one-time passwords for authentication. If you need to issue certificates to network equipment or MDM-managed mobile devices, NDES is the solution. Microsoft Docs provide a Network Device Enrollment Service(NDES) overview and even details on using a policy module with NDES for advanced scenarios (like customizing how requests are processed or integrating with custom policies). Online Responders (OCSP): As mentioned, an Online Responder can be configured to answer revocation status queries more efficiently than CRLs, especially useful if your CRLs grow large or you have high-volume certificate validation (VPNs, etc.). AD CS’s Online Responder role service can be installed on a member server and configured with the OCSP Response Signing certificate from your Issuing CA. Monitoring and Auditing: Windows Servers have options to audit CA events. Enabling auditing can log events such as certificate issuance, revocation, or changes to the CA configuration. These logs are important in enterprise PKI to track who did what (for compliance and security forensics). Also, tools like the PKI Health Tool (pkiview.msc) and PowerShell cmdlets (like Get-CertificationAuthority, Get-CertificationAuthorityCertificate) can help monitor the health and configuration of your CAs. Conclusion By following this guide, you have set up a secure two-tier PKI environment consisting of an offline Root CA and an online Issuing CA. This design, which uses an offline root, is considered a security best practice for enterprise PKI deployments because it reduces the risk of your root key being compromised. With the offline Root CA acting as a hardened trust anchor and the enterprise Issuing CA handling day-to-day certificate issuance, your lab PKI can issue certificates for various purposes (HTTPS, code signing, user authentication, etc.) in a way that models real-world deployments. As you expand this lab or move to production, always remember that PKI security is as much about process as technology. Applying strict controls to protect CA keys, keeping software up to date, and monitoring your PKI’s health are all part of the journey. For further reading and official guidance, refer to these Microsoft documentation resources: 📖 AD CS PKI Design Considerations: PKI design considerations using Active Directory Certificate Services in Windows Server helps in planning a PKI deployment (number of CAs, hierarchy depth, naming, key lengths, validity periods, etc.). This is useful to read when adapting this lab design to a production environment. It also covers configuring CDP/AIA and why offline roots usually don’t need delta CRLs. 📖 AD CS Step-by-Step Guides: Microsoft’s Test Lab Guide Test Lab Guide: Deploying an AD CS Two-Tier PKI Hierarchy walk through a similar scenario.Secure Model Context Protocol (MCP) Implementation with Azure and Local Servers
Introduction The Model Context Protocol (MCP) enables AI systems to interact with external data sources and tools through a standardized interface. While powerful, MCP can introduce security risks in enterprise environments. This tutorial shows you how to implement MCP securely using local servers, Azure OpenAI with APIM, and proper authentication. Understanding MCP's Security Risks There are a couple of key security concerns to consider before implementing MCP: Data Exfiltration: External MCP servers could expose sensitive data. Unauthorized Access: Third-party services become potential security risks. Loss of Control: Unknown how external services handle your data. Compliance Issues: Difficulty meeting regulatory requirements with external dependencies. The solution? Keep everything local and controlled. Secure Architecture Before we dive into implementation, let's take a look at the overall architecture of our secure MCP solution: This architecture consists of three key components working together: Local MCP Server - Your custom tools run entirely within your local environment, reducing external exposure risks. Azure OpenAI + APIM Gateway - All AI requests are routed through Azure API Management with Microsoft Entra ID authentication, providing enterprise-grade security controls and compliance. Authenticated Proxy - A lightweight proxy service handles token management and request forwarding, ensuring seamless integration. One of the key benefits of this architecture is that no API key is required. Traditional implementations often require storing OpenAI API keys in configuration files, environment variables, or secrets management systems, creating potential security vulnerabilities. This approach uses Azure Managed Identity for backend authentication and Azure CLI credentials for client authentication, meaning no sensitive API keys are ever stored, logged, or exposed in your codebase. For more security, APIM and Azure OpenAI resources can be configured with IP restrictions or network rules to only accept traffic from certain sources. These configurations are available for most Azure resources and provide an additional layer of network-level security. This security-forward approach gives you the full power of MCP's tool integration capabilities while keeping your implementation completely under your control. How to Implement MCP Securely 1. Local MCP Server Implementation Building the MCP Server Let's start by creating a simple MCP server in .NET Core. 1. Create a web application dotnet new web -n McpServer 2.Add MCP packages dotnet add package ModelContextProtocol --prerelease dotnet add package ModelContextProtocol.AspNetCore --prerelease 3. Configure Program.cs var builder = WebApplication.CreateBuilder(args); builder.Services.AddMcpServer() .WithHttpTransport() .WithToolsFromAssembly(); var app = builder.Build(); app.MapMcp(); app.Run(); WithToolsFromAssembly() automatically discovers and registers tools from the current assembly. Look into the C# SDK for other ways to register tools for your use case. 4. Define Tools Now, we can define some tools that our MCP server can expose. here is a simple example for tools that echo input back to the client: using ModelContextProtocol.Server; using System.ComponentModel; namespace Tools; [McpServerToolType] public static class EchoTool { [McpServerTool] [Description("Echoes the input text back to the client in all capital letters.")] public static string EchoCaps(string input) { return new string(input.ToUpperInvariant()); } [McpServerTool] [Description("Echoes the input text back to the client in reverse.")] public static string ReverseEcho(string input) { return new string(input.Reverse().ToArray()); } } Key components of MCP tools are the McpServerToolType class decorator indicating that this class contains MCP tools, and the McpServerTool method decorator with a description that explains what the tool does. Alternative: STDIO Transport If you want to use STDIO transport instead of SSE (implemented here), check out this guide: Build a Model Context Protocol (MCP) Server in C# 2. Create a MCP Client with Cline Now that we have our MCP server set up with tools, we need a client that can discover and invoke these tools. For this implementation, we'll use Cline as our MCP client, configured to work through our secure Azure infrastructure. 1. Install Cline VS Code Extension Install the Cline extension in VS Code. 2. Deploy secure Azure OpenAI Endpoint with APIM Instead of connecting Cline directly to external AI services (which could expose the secure implementation to external bad actors), we will route through Azure API Management (APIM) for enterprise security. With this implementation, all requests go through Microsoft Entra ID and we use managed identity for all authentications. Quick Setup: Deploy the Azure OpenAI with APIM solution. Ensure your Azure OpenAI resources are configured to allow your APIM's managed identity to make calls. The APIM policy below uses managed identity authentication to connect to Azure OpenAI backends. Refer to the Azure OpenAI documentation on managed identity authentication for detailed setup instructions. 3. Configure APIM Policy After deploying APIM, configure the following policy to enable Azure AD token validation, managed identity authentication, and load balancing across multiple OpenAI backends: <!-- Azure API Management Policy for OpenAI Endpoint --> <!-- Implements Azure AD Token validation, managed identity authentication --> <!-- Supports round-robin load balancing across multiple OpenAI backends --> <!-- Requests with 'gpt-5' in the URL are routed to a single backend --> <!-- The client application ID '04b07795-8ddb-461a-bbee-02f9e1bf7b46' is the official Azure CLI app registration --> <!-- This policy allows requests authenticated by Azure CLI (az login) when the required claims are present --> <policies> <inbound> <!-- IP Allow List Fragment (external fragment for client IP restrictions) --> <include-fragment fragment-id="YourCompany-IPAllowList" /> <!-- Azure AD Token Validation for Azure CLI app ID --> <validate-azure-ad-token tenant-id="YOUR-TENANT-ID-HERE" header-name="Authorization" failed-validation-httpcode="401" failed-validation-error-message="Unauthorized. Access token is missing or invalid."> <client-application-ids> <application-id>04b07795-8ddb-461a-bbee-02f9e1bf7b46</application-id> </client-application-ids> <audiences> <audience>api://YOUR-API-AUDIENCE-ID-HERE</audience> </audiences> <required-claims> <claim name="roles" match="any"> <value>YourApp.User</value> </claim> </required-claims> </validate-azure-ad-token> <!-- Acquire Managed Identity access token for backend authentication --> <authentication-managed-identity resource="https://cognitiveservices.azure.com" output-token-variable-name="managed-id-access-token" ignore-error="false" /> <!-- Set Authorization header for backend using the managed identity token --> <set-header name="Authorization" exists-action="override"> <value>@("Bearer " + (string)context.Variables["managed-id-access-token"])</value> </set-header> <!-- Check if URL contains 'gpt-5' and set backend accordingly --> <choose> <when condition="@(context.Request.Url.Path.ToLower().Contains("gpt-5"))"> <set-variable name="selected-backend-url" value="https://your-region1-oai.openai.azure.com/openai" /> </when> <otherwise> <cache-lookup-value key="backend-counter" variable-name="backend-counter" /> <choose> <when condition="@(context.Variables.ContainsKey("backend-counter") == false)"> <set-variable name="backend-counter" value="@(0)" /> </when> </choose> <set-variable name="current-backend-index" value="@((int)context.Variables["backend-counter"] % 7)" /> <choose> <when condition="@((int)context.Variables["current-backend-index"] == 0)"> <set-variable name="selected-backend-url" value="https://your-region1-oai.openai.azure.com/openai" /> </when> <when condition="@((int)context.Variables["current-backend-index"] == 1)"> <set-variable name="selected-backend-url" value="https://your-region2-oai.openai.azure.com/openai" /> </when> <when condition="@((int)context.Variables["current-backend-index"] == 2)"> <set-variable name="selected-backend-url" value="https://your-region3-oai.openai.azure.com/openai" /> </when> <when condition="@((int)context.Variables["current-backend-index"] == 3)"> <set-variable name="selected-backend-url" value="https://your-region4-oai.openai.azure.com/openai" /> </when> <when condition="@((int)context.Variables["current-backend-index"] == 4)"> <set-variable name="selected-backend-url" value="https://your-region5-oai.openai.azure.com/openai" /> </when> <when condition="@((int)context.Variables["current-backend-index"] == 5)"> <set-variable name="selected-backend-url" value="https://your-region6-oai.openai.azure.com/openai" /> </when> <when condition="@((int)context.Variables["current-backend-index"] == 6)"> <set-variable name="selected-backend-url" value="https://your-region7-oai.openai.azure.com/openai" /> </when> </choose> <set-variable name="next-counter" value="@(((int)context.Variables["backend-counter"] + 1) % 1000)" /> <cache-store-value key="backend-counter" value="@((int)context.Variables["next-counter"])" duration="300" /> </otherwise> </choose> <!-- Always set backend service using selected-backend-url variable --> <set-backend-service base-url="@((string)context.Variables["selected-backend-url"])" /> <!-- Inherit any base policies defined outside this section --> <base /> </inbound> <backend> <base /> </backend> <outbound> <base /> </outbound> <on-error> <base /> </on-error> </policies> This policy creates a secure gateway that validates Azure AD tokens from your local Azure CLI session, then uses APIM's managed identity to authenticate with Azure OpenAI backends, eliminating the need for API keys. It automatically load-balances requests across multiple Azure OpenAI regions using round-robin distribution for optimal performance. 4. Create Azure APIM proxy for Cline This FastAPI-based proxy forwards OpenAI-compatible API requests from Cline through APIM using Azure AD authentication via Azure CLI credentials, eliminating the need to store or manage OpenAI API keys. Prerequisites: Python 3.8 or higher Azure CLI (ensure az login has been run at least once) Ensure the user running the proxy script has appropriate Azure AD roles and permissions. This script uses Azure CLI credentials to obtain bearer tokens. Your user account must have the correct roles assigned and access to the target API audience configured in the APIM policy above. Quick setup for the proxy: Create this requirements.txt: fastapi uvicorn requests azure-identity Create this Python script for the proxy source code azure_proxy.py: import os import requests from fastapi import FastAPI, Request from fastapi.responses import StreamingResponse import uvicorn from azure.identity import AzureCliCredential # CONFIGURATION APIM_BASE_URL = <APIM BASE URL HERE> AZURE_SCOPE = <AZURE SCOPE HERE> PORT = int(os.environ.get("PORT", 8080)) app = FastAPI() credential = AzureCliCredential() # Use a single requests.Session for connection pooling from requests.adapters import HTTPAdapter session = requests.Session() session.mount("https://", HTTPAdapter(pool_connections=100, pool_maxsize=100)) import time _cached_token = None _cached_expiry = 0 def get_bearer_token(scope: str) -> str: """Get an access token using AzureCliCredential, caching until expiry is within 30 seconds.""" global _cached_token, _cached_expiry now = int(time.time()) if _cached_token and (_cached_expiry - now > 30): return _cached_token try: token_obj = credential.get_token(scope) _cached_token = token_obj.token _cached_expiry = token_obj.expires_on return _cached_token except Exception as e: raise RuntimeError(f"Could not get Azure access token: {e}") @app.api_route("/{path:path}", methods=["GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"]) async def proxy(request: Request, path: str): # Assemble the destination URL (preserve trailing slash logic) dest_url = f"{APIM_BASE_URL.rstrip('/')}/{path}".rstrip("/") if request.url.query: dest_url += "?" + request.url.query # Get the Bearer token bearer_token = get_bearer_token(AZURE_SCOPE) # Prepare headers (copy all, overwrite Authorization) headers = dict(request.headers) headers["Authorization"] = f"Bearer {bearer_token}" headers.pop("host", None) # Read body body = await request.body() # Send the request to APIM using the pooled session resp = session.request( method=request.method, url=dest_url, headers=headers, data=body if body else None, stream=True, ) # Stream the response back to the client return StreamingResponse( resp.raw, status_code=resp.status_code, headers={k: v for k, v in resp.headers.items() if k.lower() != "transfer-encoding"}, ) if __name__ == "__main__": # Bind the app to 127.0.0.1 to avoid any Firewall updates uvicorn.run(app, host="127.0.0.1", port=PORT) Run the setup: pip install -r requirements.txt az login # Authenticate with Azure python azure_proxy.py Configure Cline to use the proxy: Using the OpenAI Compatible API Provider: Base URL: http://localhost:8080 API Key: <any random string> Model ID: <your Azure OpenAI deployment name> API Version: <your Azure OpenAI deployment version> The API key field is required by Cline but unused in our implementation - any random string works since authentication happens via Azure AD. 5. Configure Cline to listen to your MCP Server Now that we have both our MCP server running and Cline configured with secure OpenAI access, the final step is connecting them together. To enable Cline to discover and use your custom tools, navigate to your installed MCP servers on Cline, select Configure MCP Servers, and add in the configuration for your server: { "mcpServers": { "mcp-tools": { "autoApprove": [ "EchoCaps", "ReverseEcho", ], "disabled": false, "timeout": 60, "type": "sse", "url": "http://<your localhost url>/sse" } } } Now, you can use Cline's chat interface to interact with your secure MCP tools. Try asking Cline to use your custom tools - for example, "Can you echo 'Hello World' in capital letters?" and watch as it calls your local MCP server through the infrastructure you've built. Conclusion There you have it: A secure implementation of MCP that can be tailored to your specific use case. This approach gives you the power of MCP while maintaining enterprise security. You get: AI capabilities through secure Azure infrastructure. Custom tools that never leave your environment. Standard MCP interface for easy integration. Complete control over your data and tools. The key is keeping MCP servers local while routing AI requests through your secure Azure infrastructure. This way, you gain MCP's benefits without compromising security. Disclaimer While this tutorial provides a secure foundation for MCP implementation, organizations are responsible for configuring their Azure resources according to their specific security requirements and compliance standards. Ensure proper review of network rules, access policies, and authentication configurations before deploying to production environments. Resources MCP SDKs and Tools: MCP C# SDK MCP Python SDK Cline SDK Cline User Guide Azure OpenAI with APIM Azure API Management Network Security: Azure API Management - restrict caller IPs Azure API Management with an Azure virtual network Set up inbound private endpoint for Azure API Management Azure OpenAI and AI Services Network Security: Configure Virtual Networks for Azure AI services Securing Azure OpenAI inside a virtual network with private endpoints Add an Azure OpenAI network security perimeter az cognitiveservices account network-ruleRethinking Data Security and Governance in the Era of AI
The era of AI is reshaping industries, enabling unprecedented innovations, and presenting new opportunities for organizations worldwide. But as organizations accelerate AI adoption, many are focused on a growing concern: their current data security and governance practices are not effectively built for the fast-paced AI innovation and ever-evolving regulatory landscape. At Microsoft, we recognize the critical need for an integrated approach to address these risks. In our latest findings, Top 3 Challenges in Securing and Governing Data for the Era of AI, we uncovered critical gaps in how organizations manage data risk. The findings exemplify the current challenges: 91% of leaders are not prepared to manage risks posed by AI 1 and 85% feel unprepared to comply with AI regulations 2 . These gaps not only increase non-compliance but also put innovation at risk. Microsoft Purview has the tools to tackle these challenges head on, helping organizations move to an approach that protects data, meets compliance regulations, and enables trusted AI transformation. We invite you to take this opportunity to evaluate your current practices, platforms, and responsibilities, and to understand how to best secure and govern your organization for growing data risks in the era of AI. Platform fragmentation continues to weaken security outcomes Organizations often rely on fragmented tools across security, compliance, and data teams, leading to a lack of unified visibility and insufficient data hygiene. Our findings reveal the effects of fragmented platforms, leading to duplicated data, inconsistent classification, redundant alerts, and siloed investigations, which ultimately is causing data exposure incidents related to AI to be on the rise 3 . Microsoft Purview offers centralized visibility across your organization’s data estate. This allows teams to break down silos, streamline workflows, and mitigate data leakage and oversharing. With Microsoft Purview, capabilities like data health management and data security posture management are designed to enhance collaboration and deliver enriched insights across your organization to help further protect your data and mitigate risks faster. Microsoft Purview offers the following: Unified insights across your data estate, breaking down silos between security, compliance, and data teams. Microsoft Purview Data Security Posture Management (DSPM) for AI helps organizations gain unified visibility into GenAI usage across users, data, and apps to address the heightened risk of sensitive data exposure from AI. Built-in capabilities like classification, labeling, data loss prevention, and insider risk insights in one platform. In addition, newly launched solutions like Microsoft Purview Data Security Investigations accelerate investigations with AI-powered deep content analysis, which helps data security teams quickly identify and mitigate sensitive data and security risks within impacted data. Organizations like Kern County historically relied on many fragmented systems but adopted Microsoft Purview to unify their organization’s approach to data protection in preparation for increasing risks associated with deploying GenAI. “We have reduced risk exposure, [Microsoft] Purview helped us go from reaction to readiness. We are catching issues proactively instead of retroactively scrambling to contain them.” – Aaron Nance, Deputy Chief Information Security Officer, Kern County Evolving regulations require continuous compliance AI-driven innovation is creating a surge in regulations, resulting in over 200 daily updates across more than 900 regulatory agencies 4 , as highlighted in our research. Compliance has become increasingly difficult, with organizations struggling to avoid fines and comply with varying requirements across regions. To navigate these challenges effectively, security leaders’ responsibilities are expanding to include oversight across governance and compliance, including oversight of traditional data catalog and governance solutions led by the central data office. Leaders also cite the need for regulation and audit readiness. Microsoft Purview enables compliance and governance by: Streamlining compliance with Microsoft Purview Compliance Manager templates, step-by-step guidance, and insights for region and industry-specific regulations, including GDPR, HIPAA, and AI-specific regulation like the EU AI Act. Supporting legal matters such as forensic and internal investigations with audit trail records in Microsoft Purview eDiscovery and Audit. Activating and governing data for trustworthy analytics and AI with Microsoft Purview Unified Catalog, which enables visibility across your data estate and data confidence via data quality, data lineage, and curation capabilities for federated governance. Microsoft Purview’s suite of capabilities provides visibility and accountability, enabling security leaders to meet stringent compliance demands while advancing AI initiatives with confidence. Organizations need a unified approach to secure and govern data Organizations are calling for an integrated platform to address data security, governance, and compliance collectively. Our research shows that 95% of leaders agree that unifying teams and tools is a top priority 5 and 90% plan to adopt a unified solution to mitigate data related risks and maximize impact 6 . Integration isn't just about convenience, it’s about enabling innovation with trusted data protection. Microsoft Purview enables a shared responsibility model, allowing individual business units to own their data while giving central teams oversight and policy control. As organizations adopt a unified platform approach, our findings reveal the upside potential not only being reduced risk but also cost savings. With AI-powered copilots such as Security Copilot in Microsoft Purview, data protection tasks are simplified with natural-language guidance, especially for under resourced teams. Accelerating AI transformation with Microsoft Purview Microsoft Purview helps security, compliance, and governance teams navigate the complexities of AI innovation while implementing effective data protection and governance strategies. Microsoft partner EY highlights the results they are seeing: “We are seeing 25%–30% time savings when we build secure features using [Microsoft] Purview SDK. What was once fragmented is now centralized. With [Microsoft] Purview, everything comes together on one platform, giving a unified foundation to innovate and move forward with confidence.” – Prashant Garg, Partner of Data and AI, EY We invite you to explore how you can propel your organization toward a more secure future by reading the full research paper at https://aka.ms/SecureAndGovernPaper. Visit our website to learn more about Microsoft Purview. 1 Forbes, Only 9% Of Surveyed Companies Are Ready To Manage Risks Posed By AI, 2023 2 SAP LeanIX, AI Survey Results, 2024 3 Microsoft, Data Security Index Report, 2024 4 Forbes, Cost of Compliance, Thomson Reuters, 2021 5 Microsoft, Audience Research, 2024 6 Microsoft, Customer Requirements Research, 2024Blog Series: Charting Your Path to Cyber Resiliency
Part 1: What Is Cyber Resiliency and How Do I Get It? Recently I was on a call with some Security leaders who were interested in how we at Microsoft could help them with cyber resiliency. But when I asked the questions "What does cyber resiliency mean to you?” and “What specific aspects of cyber resilience are you interested in improving?", they struggled to answer. If you're having difficulty with those questions yourself, don't worry, you're not alone. Cyber resiliency – being able to successfully continue business operations in the face of destructive cyberattacks - is having a Moment these days. It's The New Zero Trust, you might say. But what is cyber resilience really beyond an industry buzzword or a sales play? What does an organization need to do to become cyber resilient? To understand more, let's start with a look at the history of cyber resiliency and how it has evolved over the last 15 years. MITRE (best known for their ATT&CK frameworks) was an early leader in the cyber resilience movement. MITRE's 2010 publication Building Secure, Resilient Architectures for Cyber Mission Assurance, explained the need for cyber resiliency by emphasizing the operational impact of cyberattacks and the financial cost of recovery, also noting that “the cyber adversary continues to have an asymmetric advantage as we fruitlessly play Whac-A-Mole in response to individual attacks.” (Sound familiar?) One year later, MITRE released the first publication of their Cyber Resiliency Engineering Framework (CREF). In subsequent years, MITRE followed up with revisions to CREF, along with additional papers on methods and metrics for effectively measuring cyber resiliency. They also developed the CREF Navigator, an online tool to help define and graphically represent cyber resiliency goals, objectives and techniques as defined by NIST (National Institute of Standards and Technology). NIST's 2021 publication SP 800-160 Volume 2 (Rev 1): Developing Cyber-Resilient Systems is a comprehensive cyber resiliency framework that builds on CREF. It also gives us the most used definition of cyber resiliency which is: "the ability to anticipate, withstand, recover from, and adapt to adverse conditions, stresses, attacks, or compromises that use or are enabled by cyber resources." Like MITRE's early work, this publication is rooted in systems and software engineering principles and how engineers in national defense and critical infrastructure need to build resiliency into mission-critical systems. However, today we commonly apply this definition and this understanding of cyber resiliency to any organization concerned with minimizing the impact of cyberattacks on their business-critical systems. The extension of cyber resiliency principles beyond government and critical infrastructure is also evident in The EU's Cybersecurity Strategy for the Digital Decade presented in December 2020. Although this strategy was chiefly concerned with "EU institutions bodies and agencies," it also emphasized the increasing dependency of both public and private sectors on digital systems and cybersecurity, noting that financial services, digital services, and manufacturing were among the hardest hit by cybercrime. Microsoft echoed this idea in our 2022 Digital Defense Report which featured a special section on cyber resiliency, calling it “A crucial foundation of a connected society.” The report emphasized 3 key cyber resiliency themes: the critical link between cyber resiliency and business risk the importance of adapting security practices and technologies to keep up with a continuously evolving threat landscape the challenges of attaining cyber resiliency when using legacy technologies Microsoft also maintains a list of 24 key issues impacting cyber resiliency, spanning everything from legacy on-premises resources to cloud technologies and frameworks. We’ll come back to this guidance in Part 2 of our series. Conclusion Cyber resiliency is more than the latest industry buzzword. In the first part of this series, we looked at the origins of the cyber resiliency movement with a focus on 2 common cyber resiliency frameworks developed by MITRE and NIST. We also looked briefly at Microsoft’s approach and some resources we offer customers wanting to improve the resilience of critical business operations in the face of destructive cyberattacks. In the 2nd part of this series, we'll take a closer look at Microsoft's approach to cyber resiliency, from its origins in the days of Trustworthy Compute to present-day guidance on designing security solutions to mitigate the effects of ransomware. Finally, in Part 3 of the series we’ll examine how we can use AI to help with some of the most challenging components of cyber resiliency.Cybersecurity: What Every Business Leader Needs to Know Now
As a Senior Cybersecurity Solution Architect, I’ve had the privilege of supporting organisations across the United Kingdom, Europe, and the United States—spanning sectors from finance to healthcare—in strengthening their security posture. One thing has become abundantly clear: cybersecurity is no longer the sole domain of IT departments. It is a strategic imperative that demands attention at board-level. This guide distils five key lessons drawn from real-world engagements to help executive leaders navigate today’s evolving threat landscape. These insights are not merely technical—they are cultural, operational, and strategic. If you’re a C-level executive, this article is a call to action: reassess how your organisation approaches cybersecurity before the next breach forces the conversation. In this article, I share five lessons (and quotes) from the field that help demystify how to enhance an organisation’s security posture. 1. Shift the Mindset “This has always been our approach, and we’ve never experienced a breach—so why should we change it?” A significant barrier to effective cybersecurity lies not in the sophistication of attackers, but in the predictability of human behaviour. If you’ve never experienced a breach, it’s tempting to maintain the status quo. However, as threats evolve, so too must your defences. Many cyber threats exploit well-known vulnerabilities that remain unpatched or rely on individuals performing routine tasks in familiar ways. Human nature tends to favour comfort and habit—traits that adversaries are adept at exploiting. Unlike many organisations, attackers readily adopt new technologies to advance their objectives, including AI-powered ransomware to execute increasingly sophisticated attacks. It is therefore imperative to recognise—without delay—that the advent of AI has dramatically reduced both the effort and time required to compromise systems. As the UK’s National Cyber Security Centre (NCSC) has stated: “AI lowers the barrier for novice cyber criminals, hackers-for-hire and hacktivists to carry out effective access and information gathering operations. This enhanced access will likely contribute to the global ransomware threat over the next two years.” Similarly, McKinsey & Company observed: “As AI quickly advances cyber threats, organisations seem to be taking a more cautious approach, balancing the benefits and risks of the new technology while trying to keep pace with attackers’ increasing sophistication.” To counter this evolving threat landscape, organisations must proactively leverage AI in their cyber defence strategies. Examples include: Identity and Access Management (IAM): AI enhances IAM by analysing real-time signals across systems to detect risky sign-ins and enforce adaptive access controls. Example: Microsoft Entra Agents for Conditional Access use AI to automate policy recommendations, streamlining access decisions with minimal manual input. Figure 1: Microsoft Entra Agents Threat Detection: AI accelerates detection, response, and recovery, helping organisations stay ahead of sophisticated threats. Example: Microsoft Defender for Cloud’s AI threat protection identifies prompt injection, data poisoning, and wallet attacks in real time. Incident Response: AI facilitates real-time decision-making, removing emotional bias and accelerating containment and recovery during security incidents. Example: Automatic Attack Disruption in Defender XDR, which can automatically contain a breach in progress. AI Security Posture Management AI workloads require continuous discovery, classification, and protection across multi-cloud environments. Example: Microsoft Defender for Cloud’s AI Security Posture Management secures custom AI apps across Azure, AWS, and GCP by detecting misconfigurations, vulnerabilities, and compliance gaps. Data Security Posture Management (DSPM) for AI AI interactions must be governed to ensure privacy, compliance, and insider risk mitigation. Example: Microsoft Purview DSPM for AI enables prompt auditing, applies Data Loss Prevention (DLP) policies to third-party AI apps like ChatGPT, and supports eDiscovery and lifecycle management. AI Threat Protection Organisations must address emerging AI threat vectors, including prompt injection, data leakage, and model exploitation. Example: Defender for AI (private preview) provides model-level security, including governance, anomaly detection, and lifecycle protection. Embracing innovation, automation, and intelligent defence is the secret sauce for cyber resilience in 2026. 2. Avoid One-Off Purchases – Invest with a Strategy “One MDE and one Sentinel to go, please.” Organisations often approach me intending to purchase a specific cybersecurity product—such as Microsoft Defender for Endpoint (MDE)—without a clearly articulated strategic rationale. My immediate question is: what is the broader objective behind this purchase? Is it driven by perceived value or popularity, or does it form part of a well-considered strategy to enhance endpoint security? Cybersecurity investments should be guided by a long-term, holistic strategy that spans multiple years and is periodically reassessed to reflect evolving threats. Strengthening endpoint protection must be integrated into a wider effort to improve the organisation’s overall security posture. This includes ensuring seamless integration between security solutions and avoiding operational silos. For example, deploying robust endpoint protection is of limited value if identities are not safeguarded with multi-factor authentication (MFA), or if storage accounts remain publicly accessible. A cohesive and forward-looking approach ensures that all components of the security architecture work in concert to mitigate risk effectively. Security Adoption Journey (Based on Zero Trust Framework) Assess – Evaluate the threat landscape, attack surface, vulnerabilities, compliance obligations, and critical assets. Align – Link security objectives to broader business goals to ensure strategic coherence. Architect – Design integrated and scalable security solutions, addressing gaps and eliminating operational silos. Activate – Implement tools with robust governance and automation to ensure consistent policy enforcement. Advance – Continuously monitor, test, and refine the security posture to stay ahead of evolving threats. Security tools are not fast food—they work best as part of a long-term plan, not a one-off order. This piecemeal approach runs counter to the modern Zero Trust security model, which assumes no single tool will prevent every breach and instead implements layered defences and integration. 3. Legacy Systems Are Holding You Back “Unfortunately, we are unable to implement phishing-resistant MFA, as our legacy app does not support integration with the required protocols.” A common challenge faced by many organisations I have worked with is the constraint on innovation within their cybersecurity architecture, primarily due to continued reliance on legacy applications—often driven by budgetary or operational necessity. These outdated systems frequently lack compatibility with modern security technologies and may introduce significant vulnerabilities. A notable example is the deployment of phishing-resistant multi-factor authentication (MFA)—such as FIDO2 security keys or certificate-based authentication—which requires advanced identity protocols and conditional access policies. These capabilities are available exclusively through Microsoft Entra ID. To address this issue effectively, it is essential to design security frameworks based on the organisation’s future aspirations rather than its current limitations. By adopting a forward-thinking approach, organisations can remain receptive to emerging technologies that align with their strategic cybersecurity objectives. Moreover, this perspective encourages investment in acquiring the necessary talent, thereby reducing reliance on extensive change management and staff retraining. I advise designing for where you want to be in the next 1–3 years—ideally cloud-first and identity-driven—essentially adopting a Zero Trust architecture, rather than being constrained by the limitations of legacy systems. 4. Collaboration Is a Security Imperative “This item will need to be added to the dev team's backlog. Given their current workload, they will do their best to implement GitHub Security in Q3, subject to capacity.” Cybersecurity threats may originate from various parts of an organisation, and one of the principal challenges many face is the fragmented nature of their defence strategies. To effectively mitigate such risks, cybersecurity must be embedded across all departments and functions, rather than being confined to a single team or role. In many organisations, the Chief Information Security Officer (CISO) operates in isolation from other C-level executives, which can limit their influence and complicate the implementation of security measures across the enterprise. Furthermore, some teams may lack the requisite expertise to execute essential security practices. For instance, an R&D lead responsible for managing developers may not possess the necessary skills in DevSecOps. To address these challenges, it is vital to ensure that the CISO is empowered to act without political or organisational barriers and is supported in implementing security measures across all business units. When the CISO has backing from the COO and HR, initiatives such as MFA rollout happen faster and more thoroughly. Cross-Functional Security Responsibilities Role Security Responsibilities R&D - Adopt DevSecOps practices - Identify vulnerabilities early - Manage code dependencies - Detect exposed secrets - Embed security in CI/CD pipelines CIO - Ensure visibility over organizational data - Implement Data Loss Prevention (DLP) - Safeguard sensitive data lifecycle - Ensure regulatory compliance CTO - Secure cloud environments (CSPM) - Manage SaaS security posture (SSPM) - Ensure hardware and endpoint protection COO - Protect digital assets - Secure domain management - Mitigate impersonation threats - Safeguard digital marketing channels and customer PII Support & Vendors - Deliver targeted training - Prevent social engineering attacks - Improve awareness of threat vectors HR - Train employees on AI-related threats - Manage insider risks - Secure employee data - Oversee cybersecurity across the employee lifecycle Empowering the CISO to act across departments helps organisations shift towards a security-first culture—embedding cybersecurity into every function, not just IT. 5. Compliance Is Not Security “We’re compliant, so we must be secure.” Many organisations mistakenly equate passing audits—such as ISO 27001 or SOC 2—with being secure. While compliance frameworks help establish a baseline for security, they are not a guarantee of protection. Determined attackers are not deterred by audit checklists; they exploit gaps, misconfigurations, and human error regardless of whether an organisation is certified. Moreover, due to the rapidly evolving nature of the cyber threat landscape, compliance frameworks often struggle to keep pace. By the time a standard is updated, attackers may already be exploiting new techniques that fall outside its scope. This lag creates a false sense of security for organisations that rely solely on regulatory checkboxes. Security is a continuous risk management process—not a one-time certification. It must be embedded into every layer of the enterprise and treated with the same urgency as other core business priorities. Compliance may be the starting line, not the finish line. Effective security goes beyond meeting regulatory requirements—it demands ongoing vigilance, adaptability, and a proactive mindset. Conclusion: Cybersecurity Is a Continuous Discipline Cybersecurity is not a destination—it is a continuous journey. By embracing strategic thinking, cross-functional collaboration, and emerging technologies, organisations can build resilience against today’s threats and tomorrow’s unknowns. The lessons shared throughout this article are not merely technical—they are cultural, operational, and strategic. If there is one key takeaway, it is this: avoid piecemeal fixes and instead adopt an integrated, future-ready security strategy. Due to the rapidly evolving nature of the cyber threat landscape, compliance frameworks alone cannot keep pace. Security must be treated as a dynamic, ongoing process—one that is embedded into every layer of the enterprise and reviewed regularly. Organisations should conduct periodic security posture reviews, leveraging tools such as Microsoft Secure Score or monthly risk reports, and stay informed about emerging threats through threat intelligence feeds and resources like the Microsoft Digital Defence Report, CISA (Cybersecurity and Infrastructure Security Agency), NCSC (UK National Cyber Security Centre), and other open-source intelligence platforms. As Ann Johnson aptly stated in her blog: “The most prepared organisations are those that keep asking the right questions and refining their approach together.” Cyber resilience demands ongoing investment—in people (through training and simulation drills), in processes (via playbooks and frameworks), and in technology (through updates and adoption of AI-driven defences). To reduce cybersecurity risk over time, resilient organisations must continually refine their approach and treat cybersecurity as an ongoing discipline. The time to act is now. Resources: https://www.ncsc.gov.uk/report/impact-of-ai-on-cyber-threat Defend against cyber threats with AI solutions from Microsoft - Microsoft Industry Blogs Generative AI Cybersecurity Solutions | Microsoft Security Require phishing-resistant multifactor authentication for Microsoft Entra administrator roles - Microsoft Entra ID | Microsoft Learn AI is the greatest threat—and defense—in cybersecurity today. Here’s why. Microsoft Entra Agents - Microsoft Entra | Microsoft Learn Smarter identity security starts with AI https://www.microsoft.com/en-us/security/blog/2025/06/12/cyber-resilience-begins-before-the-crisis/ https://www.microsoft.com/en-us/security/security-insider/threat-landscape/microsoft-digital-defense-report-2023-critical-cybersecurity-challenges https://www.microsoft.com/en-us/security/blog/2025/06/12/cyber-resilience-begins-before-the-crisis/
