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New Blog

I recently decided to use Blogger.com for my blogging activity. Here is the URL of the new blog: http://blog.malerisch.net

All previous articles and research can still be found at my previous site: http://malerisch.net

In future, articles will only appear here. So make sure to bookmark this site or follow feeds to get timely updates.

Thanks for your attention.

Popular posts from this blog

Pwning a thin client in less than two minutes

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Microsoft .NET MVC ReDoS (Denial of Service) Vulnerability - CVE-2015-2526 (MS15-101)

Microsoft released a security bulletin ( MS15-101 ) describing a .NET MVC Denial of Service vulnerability ( CVE-2015-2526 ) that I reported back in April. This blog post analyses the vulnerability in details, starting from the theory and then providing a PoC exploit against a MVC web application developed with Visual Studio 2013. For those of you who want to see the bug, you can directly skip to the last part of this post or watch the video directly... ;-) A bit of theory The .NET framework (4.5 tested version) uses backtracking regular expression matcher when performing a match against an expression. Backtracking is based on the NFA (non-deterministic finite automata) algorithm engine which is designed to validate all input states. By providing an “evil” regex expression – an expression for which the engine can be forced to calculate an exponential number of states - it is possible to force the engine to calculate an exponential number of states, leading to a condition defined su

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