The IRC Protocol component in KVIrc 3.x and 4.x before r4693 does not properly handle \ (backslash) characters, which allows remote authenticated users to execute arbitrary CTCP commands via vectors involving \r and \40 sequences, a different vulnerability than CVE-2010-2451 and CVE-2010-2452.

Multiple format string vulnerabilities in the DCC functionality in KVIrc 3.4 and 4.0 have unspecified impact and remote attack vectors.

Directory traversal vulnerability in the DCC functionality in KVIrc 3.4 and 4.0 allows remote attackers to overwrite arbitrary files via unknown vectors.

Format string vulnerability in the URI handler in KVirc 3.4.0, when set as the default application for processing IRC URIs, allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via format string specifiers in the irc:// URI.