ZenHAX

Basically the attackers can upload files (dll in this specific exploitation) on clients and servers of Gmod and other Source games:

http://steamcommunity.com/games/garrysm ... 2135333176

Some notes:

• the changelog is dated end of April 2014
• it's stated that the bug still affects the games based on the Source engine
• it has been actively exploited in the wild = very very very bad
• "As far as we are aware the exploit wasn’t used to do anything malicious beyond propagating itself, spamming chat and changing server names"

I guess that the issue is somewhat related to these old vulnerabilities dated 2009, yes 5 years ago:
http://aluigi.org/adv/sourceupfile-adv.txt
http://www.facepunch.com/showthread.php?t=854605

It's not the first time that I see security issues affecting the Source engine that are partially fixed or can be replicated in other ways.

It seems like an alternative version of the bug has surfaced and being used. There are a lot of threads and other things going around so I'm not positive about anything, and I haven't seen any of the videos before they were taken down, but I would not be surprised, since it is far from the first time Valve's bandaid patches have not worked.

More related info: https://facepunch.com/showthread.php?t= ... st49521034