CODEWITHSUNDEEP
asp.netiisexception
Hafthor
Hafthor

Reputation: 16906

Strange Request URLs in logged ASP.NET exceptions, but not in IIS logs

Getting unhandled exception event log messages for legitimate exceptions but the event log message includes noise in the request URL.

The noise is injected where uri escaped characters are. Noise like the apppool name, "An unhandled exception has occurred.", False and sometimes the request url itself recursively injected, sometimes a dozen times inside the url. The IIS logs don't show this injection, just the original url.

Here's one of the recursive examples:

Request URL: http://domain.com/Page.aspx?q=bransonAn unhandled exception has occurred.Chttp://domain.com/Page.aspx?q=bransonAn unhandled exception has occurred.Chttp://domain.com/Page.aspx?q=bransonAn unhandled exception has occurred.Chttp://domain.com/Page.aspx?q=branson%2C%20momomomo

The one somewhat unusual thing about the code is that it uses an exception filter which does some logging and then returns false, allowing the exception to go unhandled.

Upvotes: 2

Views: 466

Answers (1)

Liam
Liam

Reputation: 21

I've encountered the same issue as described above and after a few days on Google have come up with the what caused it (well for me anyway) and thought that I'd share - Even though this discussion is over a year old.

It was caused by spaces being included in the query string, which were getting changed to %20. When an exception was getting raised within the code it appears that IIS (or the Development Server in Visual Studio 2008) was, possibly, assuming that the %20 was a parameter to be passed in to the exception handler and building up the crazy looking Request URL - It was always contained 82 times within the log and no where I searched mentioned this.

In the web.config the encoding can be managed through the globalization section, but this didn't resolve our issue - It turns out that if you use RFC2396, then you don't get this issue. We're now replacing our spaces with a non-breakable space character and this is working so far in our testing.

Upvotes: 2

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