A single user is receiving a Runtime Error when logging into RD Web Access (Server 2012). I did notice an event pop up in the Application log:
Level: Warning
Source: ASP.NET 4.0.303190
Event ID: 1309
Task Category: Web Event
Event code: 3003
Event message: A validation error has occurred.
Event time: 8/5/2013 9:23:11 AM
Event time (UTC): 8/5/2013 1:23:11 PM
Event ID: db80b8f6c5f54803a050624241698c18
Event sequence: 3302
Event occurrence: 13
Event detail code: 0
Application information:
Application domain: /LM/W3SVC/1/ROOT/RDWeb/Pages-2-130171705261678145
Trust level: Full
Application Virtual Path: /RDWeb/Pages
Application Path: C:\Windows\Web\RDWeb\Pages\
Machine name: VDICB12KDC01
Process information:
Process ID: 1044
Process name: w3wp.exe
Account name: IIS APPPOOL\RDWebAccess
Exception information:
Exception type: HttpRequestValidationException
Exception message: A potentially dangerous Request.Form value was detected from the client (UserPass="sfjt<KADM").
at System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection)
at System.Web.HttpRequest.ValidateHttpValueCollection(HttpValueCollection collection, RequestValidationSource requestCollection)
at Microsoft.TerminalServices.Publishing.Portal.FormAuthentication.TSFormsAuthentication.ExtractInfoFromForm(HttpContext objHttpContext)
at Microsoft.TerminalServices.Publishing.Portal.FormAuthentication.TSFormsAuthentication.OnAuthenticateRequest(Object source, EventArgs e)
at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
Request information:
Request URL: https://<server>:443/RDWeb/Pages/en-US/login.aspx
Request path: /RDWeb/Pages/en-US/login.aspx
User host address: 10.77.110.77
User:
Is authenticated: False
Authentication Type:
Thread account name: IIS APPPOOL\RDWebAccess
Thread information:
Thread ID: 14
Thread account name: IIS APPPOOL\RDWebAccess
Is impersonating: False
Stack trace: at System.Web.HttpRequest.ValidateString(String value, String collectionKey, RequestValidationSource requestCollection)
at System.Web.HttpRequest.ValidateHttpValueCollection(HttpValueCollection collection, RequestValidationSource requestCollection)
at Microsoft.TerminalServices.Publishing.Portal.FormAuthentication.TSFormsAuthentication.ExtractInfoFromForm(HttpContext objHttpContext)
at Microsoft.TerminalServices.Publishing.Portal.FormAuthentication.TSFormsAuthentication.OnAuthenticateRequest(Object source, EventArgs e)
at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)