ASP.NET security patch, what's changed

I've snooped around with fiddler to see what changes have been introduced by the patch release today for the ASP.NET framework.

I've seen to notable differences in the behaviour of webresource.axd:

1. The d parameter is now set to a value much longer than before, it seems it's 50 bytes longer
2. Tampering with this parameter will not trigger a 500 server error and an entry in the application event log. A regular 404 error is returned to the browser, and nothing is logged in the event log.

My guess is that they have included an integrity check of some kind. Also, they've fixed the problem with error messages distinguishing between the different errors occuring. Now, it's all 404 errors.

Anyhow, it's time to go home from work. Unfortunately, my local time is quite far from PDT. Happy patching!