Crafty Game Stack Overflow & Exploit

[Angelo Rosiello <angelo.rosiello () katamail com>]

                   Copyright © Rosiello Security 
                      http://www.rosiello.org


ADVISORY: http://www.rosiello.org/en/read_bugs.php?18
BACKGROUND: by SecurityTracker
EXPLOIT: http://www.rosiello.org/archivio/crafty.zip

Impact: Execution of arbitrary code via local system, User access via local system 
Version(s): 19.3 and prior versions 
Description: A vulnerability was reported in the Crafty game. A local user may be able to gain elevated privileges on 
the target system, depending on the configuration. 

It is reported that 'crafty.bin' does not properly check the bounds of user-supplied command line data. A local user 
can supply specially crafted values to trigger a buffer overflow and execute arbitrary code with the privileges of 
Crafty. On some Linux distributions, Crafty is installed with set group id (setgid) 'games' group privileges. 

Steve Kemp reported this vulnerability. 

Impact: A local user can execute arbitrary code with the privileges of Crafty, which may be 'games' group privileges on 
some distributions. 

Solution: It appears that no upstream fix was available at the time of this entry. The vendor notes that Crafty is not 
installed with set user id (setuid) or set group id (setgid) privileges, so there would be no security impact. However, 
some Linux distributions may install with setuid or setgid privileges. 

Vendor URL: www.limunltd.com/crafty/ (Links to External Site) 
Cause: Boundary error 
Underlying OS: Linux (Any), UNIX (Any) 

The exploit contains a bruteforce written in perl to get run time the right offset of the machine.