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Archive for June, 2012

Quake 3 Source Code Review by Fabian Sanglard

Saturday, June 30th, 2012

Fabian Sanglard:

I was particularly impressed by :

  • The virtual machines system and the associated toolchain that altogether account for 30% of the code released. Under this perspective idTech3 is a mini operating system providing system calls to three processes.
  • The elegant network system based on snapshots and memory introspection.

Check out his entire code review here.

Open Source Tools for Game Development

Thursday, June 21st, 2012

Ryan spoke again at Flourish, and here’s the video:

 

Notes are here:

http://icculus.org/flourish/

CVE-2012-3345 symlink attack in ioquake3 >= r1773

Thursday, June 14th, 2012
Background
==========
 
ioquake3 [IOQ] is a fork of the Quake III Arena (id Tech 3) game engine,
and has become the de facto upstream for that engine since id Software
ceased to develop it. It is also used (unmodified, modified or forked)
in various open-source and proprietary games including OpenArena [OA],
Reaction [REA], Smokin’ Guns [SGN], Tremulous [TREM], Turtle Arena [TA],
Urban Terror [URT] and World of Padman [WOP].
 
Vulnerability
=============
 
Access vector: local
Authentication required: local system
Impact: overwrite a file owned by the victim with a predictable integer
 
Since svn revision 1773, ioquake3 has written its process ID to the file
/tmp/ioq3.pid (or ioq3.pid in a world-writeable location) under the
following circumstances:
 
* running on non-Mac Unix and TMPDIR not set, or set to a
world-writeable location; or
* running on Mac OS and FSFindFolder() for a temporary directory fails
or returns a world-writeable location
 
On a multi-user system, an attacker could create a symbolic link
/tmp/ioq3.pid pointing to any file owned by a user who plays an
ioquake3-based game. When the victim runs ioquake3, the target file will
be overwritten and replaced with the process ID of ioquake3.
 
The effect of this attack depends on the file being overwritten: it
could be simple vandalism (destroy one of the victim’s files), or it
could have further security implications if knowledge of the contents of
a target file is used for authentication (in a system similar to
pam_dotfile [DOT], for instance).
 
For the dedicated server, the process ID is written to ioq3_server.pid,
but the attack is essentially the same. For forks of ioquake3, the
filename will typically include the name of the fork, e.g. openarena.pid.
 
Affected versions
=================
 
* ioquake3 >= svn r1773
* ioquake3 < svn r2253
* OpenArena 0.8.8
* Reaction beta 1.0
* Smokin’ Guns 1.1
* Tremulous “trunk” >= svn r2125
* Tremulous “gpp” >= svn r2140
* Turtle Arena >= svn r204 (all releases named Turtle Arena)
* World of Padman >= 1.5.2 beta
 
Unaffected versions
===================
 
* ioquake3 1.36
* ioquake3 <= svn r1772
* ioquake3 >= svn r2253
* OpenArena <= 0.8.5
* Smokin’ Guns <= 1.1b4
* Tremulous “trunk” <= svn r2124
* Tremulous “gpp” <= svn r2139
* Tremulous GPP1
* Tremulous <= 1.1.0
* Turtle Arena <= svn r203
* TMNT Arena 20091211 (former name of Turtle Arena)
* ioUrbanTerror 2007-12-20 client
* ioUrbanTerror 2007-12-20 server
* World of Padman <= 1.5.0
 
Solution
========
 
The attached patches have been reviewed by two ioquake3 maintainers.
Please apply them to affected versions on or after the embargo date.
 
Patch 0001 fixes the vulnerability by writing the pid file into the
ioquake3 user’s home directory (e.g. ~/.q3a/ioq3.pid for an unmodified
engine with default configuration) instead of the temporary directory.
 
Patch 0002 is recommended, but not strictly necessary to fix the
vulnerability. It removes the functions to get the temporary directory,
as a precaution against other unsafe uses.
 
 
References
==========
 

Calling all content creators!

Saturday, June 2nd, 2012

Work has started on “baseio“, a project to create a small game to include with the ioquake3 engine download with Creative Commons licensed content. Work has already been started on textures, weapon models, and a player model, but there is still much to be done. Animations, mapping, and audio are most needed, but if there’s anything you can contribute, join the discussion. Any content contributed must be under a Creative Commons nonccommercial-by-sharealike license. The ioquake3 code base and any contributed code will remain GPL. We also need some people who have lead mods before since we’ve run out of beer so now we’re too sober to know what to do.