Bug#598285: bristol: CVE-2010-3351: insecure library loading

[Raphael Geissert]

Package: bristol
Version: 0.60.5-1+b1
Severity: grave
Tags: security
User: team at security.debian.org
Usertags: ldpath

Hello,

During a review of the Debian archive, I've found your package to
contain a script that can be abused by an attacker to execute arbitrary
code.

The vulnerability is introduced by an insecure change to
LD_LIBRARY_PATH, and environment variable used by ld.so(8) to look for
libraries on a directory other than the standard paths.

Vulnerable code follows:

/usr/bin/startBristol line 350:
export LD_LIBRARY_PATH=/usr/local/lib:usr/lib:${LD_LIBRARY_PATH}:${BRISTOL}/lib

When there's an empty item on the colon-separated list of
LD_LIBRARY_PATH, ld.so treats it as '.' (i.e. CWD/$PWD.)
If the given script is executed from a directory where a potential,
local, attacker can write files to, there's a chance to exploit this
bug.

Note that there's also a missing slash on the second entry (_usr_/lib.)

This vulnerability has been assigned the CVE id CVE-2010-3351. Please make sure
you mention it when forwarding this report to upstream and when fixing
this bug (everywhere: upstream and here at Debian.)

[0] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3351
[1] http://security-tracker.debian.org/tracker/CVE-2010-3351

Sincerely,
Raphael Geissert