Note: this post is getting frequent updates; please keep checking back. Last update: 3/19/2021
Microsoft has released a set of out of band security updates for vulnerabilities for the following ver...
Updated Mar 19, 2021
Version 44.0
Blog Post
Since installing the security update I've been seeing an "Invalid input value" periodically logged in the Application log. I wonder if this is coming from the attacker still trying to get into the system.
[Ecp] An internal server error occurred. The unhandled exception was: System.ArgumentException: Invalid input value
Parameter name: input
at Microsoft.Exchange.Data.ApplicationLogic.Cafe.BackEndServer.FromString(String input)
at Microsoft.Exchange.HttpProxy.BEResourceRequestHandler.ResolveAnchorMailbox()
at Microsoft.Exchange.HttpProxy.ProxyRequestHandler.InternalBeginCalculateTargetBackEnd(AnchorMailbox& anchorMailbox)
at Microsoft.Exchange.HttpProxy.ProxyRequestHandler.<BeginCalculateTargetBackEnd>b__3b()
at Microsoft.Exchange.Common.IL.ILUtil.DoTryFilterCatch(TryDelegate tryDelegate, FilterDelegate filterDelegate, CatchDelegate catchDelegate)