Some vulnerabilities have been discovered in KVIrc, which potentially can be exploited by malicious people to compromise a user's system.

1) A format string error while processing URIs can be exploited e.g. by tricking a user into opening a specially crafted "irc://" URI.

Successful exploitation may allow execution of arbitrary code, but requires that KVIrc is the default handler for IRC URIs.

2) Certain parts of the URI are not properly sanitised when building the command for KVIrc's internal script system. This can be exploited to inject and execute commands for the KVIrc script system (including the "run" command, which can be leveraged to execute shell commands) by e.g. tricking a user into opening a malicious "irc://" (or similar URI like "irc6://") URI.

Vulnerability #1 is confirmed in version 3.4.0 on Windows and vulnerability #2 is confirmed in version 3.4.2. Other versions may also be affected.

3) Insufficient sanitation of input data when handling DCC requests can be exploited to e.g. overwrite arbitrary files by tricking a user into accepting a malicious DCC request containing directory traversal sequences.

Note: Format string errors with unknown impact have also been reported within the DCC handling code.

Solution
Do not follow untrusted links or browse untrusted websites.
Further details available to Secunia VIM customers

Provided and/or discovered by
1) Gjoko 'LiquidWorm' Krstic
2) strawdog
3) The vendor credits an anonymous person.

Changelog
Further details available to Secunia VIM customers

Original Advisory
1) http://milw0rm.com/exploits/6832
2) http://milw0rm.com/exploits/7181
3) http://lists.omnikron.net/pipermail/kvirc/2010-May/000867.html
https://svn.kvirc.de/kvirc/changeset/4335/branches

Deep Links
Links available to Secunia VIM customers