Repetitive error

[Rasika WIJAYARATNE]

Hi guys,

We get the below error on our temple website every 2 hours or so; I
think someone is trying to hijack the 'contact.aspx' page somehow to
send spam emails, I am not sure though.

The strange thing is the 'referer' is 'contact.aspx' and the 'path' is
an article on the website ('blind_eye.aspx'). EVERY TIME this error
happens these two pages are involved, so I am guessing it is an
intentional act by someone that is causing this.

Does anyone know what is actually happening below and how to put a
stop to it, as it happens every two hours?


System.Web.HttpException: The state information is invalid for this
page and might be corrupted. ---> System.Web.UI.ViewStateException:
Invalid viewstate.
Client IP: 201.37.174.74
Port: 2271
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;
SV1)
ViewState: /wEPDwUKLTU4MDE5NTg0NWRkKYJWzJJxaGEwGDqBITc+XW3yRT0
Referer: http://vihara.org.au/t7/contact.aspx
Path: /t7/youth/articles/authors/rasikaw/blind_eye.aspx --->
System.FormatException: Invalid length for a Base-64 char array.
at System.Convert.FromBase64String(String s)
at System.Web.UI.ObjectStateFormatter.Deserialize(String
inputString)
at
System.Web.UI.ObjectStateFormatter.System.Web.UI.IStateFormatter.Deserialize(String
serializedState)
at System.Web.UI.Util.DeserializeWithAssert(IStateFormatter
formatter, String serializedState)
at System.Web.UI.HiddenFieldPageStatePersister.Load()
--- End of inner exception stack trace ---
--- End of inner exception stack trace ---
at System.Web.UI.ViewStateException.ThrowError(Exception inner,
String persistedState, String errorPageMessage, Boolean
macValidationError)
at System.Web.UI.HiddenFieldPageStatePersister.Load()
at System.Web.UI.Page.LoadPageStateFromPersistenceMedium()
at System.Web.UI.Page.LoadAllState()
at System.Web.UI.Page.ProcessRequestMain(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean
includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext
context)
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at
ASP.youth_articles_authors_rasikaw_blind_eye_aspx.ProcessRequest(HttpContext
context)
at
System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step,
Boolean& completedSynchronously)

 

[John Timney \(MVP\)]

If its repetitive, see if you can identify the IP of the request initiator
and block it in IIS.

Regards

John Timney (MVP)
http://www.johntimney.com
http://www.johntimney.com/blog

 

[Juan T. Llibre]

If you're using ASP.NET 1.1, reading this KB might help you :
http://support.microsoft.com/default.aspx/kb/831150

There's background info on this problem at :
http://support.microsoft.com/default.aspx?scid=KB;en-us;q316920