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.

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).

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.