Heap-based buffer overflow in Xchat-WDK before 1499-4 (2012-01-18) xchat 2.8.6 on Maemo architecture could allow remote attackers to cause a denial of service (xchat client crash) or execute arbitrary code via a UTF-8 line from server containing characters outside of the Basic Multilingual Plane (BMP).

Argument injection vulnerability in XChat 2.8.7b and earlier on Windows, when Internet Explorer is used, allows remote attackers to execute arbitrary commands via the --command parameter in an ircs:// URI.

Heap-based buffer overflow in XChat 2.8.9 and earlier allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long response string.

Untrusted search path vulnerability in the Python module of xchat allows local users to execute arbitrary code via a Trojan horse Python file in the current working directory, related to an erroneous setting of sys.path by the PySysSetArgv function.

References (test case, PoC): http://www.nabble.com/Bug-484305%3A-bicyclerepair%3A-bike.vim-imports-untrusted-python-files-from-cwd-td18848099.html

Proposed patch: The Debian patch for similar dia's Python related issue, available at:

http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=5;filename=pythonpath.diff;att=1;bug=504251

should be sufficient to resolve this issue.