The vulnerability is introduced by an insecure change to LD_LIBRARY_PATH, an environment variable used by ld.so(8) to look for libraries on a directory other than the standard paths. Vulnerable code follows: /usr/lib/texmacs/TeXmacs/bin/tm_mupad_help line 29: LD_LIBRARY_PATH=$LD_LIBRARY_PATH:${MuPAD_ROOT_PATH}/${SYSINFO}/lib:/usr/local/X11R6/motif-2.0/lib:/usr/local/X11R6/lib:$MuPAD_ROOT_PATH/$SYSINFO/bin /usr/bin/texmacs line 30: LD_LIBRARY_PATH="$TEXMACS_BIN_PATH/lib${LD_LIBRARY_PATH+":$LD_LIBRARY_PATH"}" 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.
TeXmacs-1.0.7.7-alt1 -> sisyphus: * Sat Oct 23 2010 Ilya Mashkin <oddity@altlinux> 1.0.7.7-alt1 - 1.0.7.7 - fix CVE-2010-3394 (Etienne Millon) (Closes: #24328)