Oops. Blog update.

I know, I suck at updating my blog lately. I guess it’s because I can use twitter to post little things now, so don’t feel the need to expand on them in a big blog post.

There’s another big exploit in the Source DS. Basically, it lets clients download and upload any file to/from a server. I haven’t emailed Valve about it – I assume they know and are working on a patch for it asap. (Which will hopefully be applied to GMod’s server too this time!).

Here’s the post AzuiSleet kindly posted on HLDS:

It seems the upload/download exploits aren’t dead yet, and Valve didn’t do a good job at patching them. A blacklist didn’t work too well. Here is a serverplugin POC to upload and download files. It’s fairly trivial to use:

download_file cfg/server.cfg
upload_file addons/serverplugin_sample.dll

upload_file doesn’t work in TF2, but download_file does. I’m told you can upload DLLs in Gmod and L4D2. Credit to Chrisaster and the rest of the Gmod scene.

Codename “Source Engine Suck Server Pwner” in memory of nitro2o:
http://dl.dropbox.com/u/759758/sourcenginesuck_serverowner.7z

Source:
http://azu.pastebin.com/m1cd1ab0b

So.. you might want to either shut your servers down for the time being, or protect them. Protecting them involves installing some server addon or something. I haven’t really looked into it too much – so do your own research. I’ve just shut my server down for now (as I was already finding runme.exe in the game folder).

To be honest, this kind of exploit really does surprise me. I’m not the greatest coder in the world but if I was coding some system that allowed clients to upload files to the server – the first thing in my mind would be “don’t let them upload exe’s to the server”. If I was coding something to let clients download stuff from the server, the first thing in my mind would be “don’t let them download any file they want”. But maybe it’s more complicated than that, I dunno.