rxvt-unicode before 9.20 does not properly handle OSC escape sequences, which allows user-assisted remote attackers to manipulate arbitrary X window properties and execute arbitrary commands.
dist.schmorp.de/rxvt-unicode/Changes
lists.opensuse.org/opensuse-security-announce/2014-06/msg00026.html
lists.opensuse.org/opensuse-updates/2014-06/msg00038.html
seclists.org/oss-sec/2014/q2/204
www.debian.org/security/2014/dsa-2925
www.securityfocus.com/bid/67155
lists.fedoraproject.org/pipermail/package-announce/2014-May/133166.html
lists.fedoraproject.org/pipermail/package-announce/2014-May/133195.html