The selinux_ip_postroute_iptables_compat function in security/selinux/hooks.c in the SELinux subsystem in the Linux kernel before 2.6.27.22, and 2.6.28.x before 2.6.28.10, when compat_net is enabled, omits calls to avc_has_perm for the (1) node and (2) port, which allows local users to bypass intended restrictions on network traffic. NOTE: this was incorrectly reported as an issue fixed in 2.6.27.21.
https://launchpad.net/bugs/cve/2009-1184
http://www.ubuntu.com/usn/usn-793-1
http://www.openwall.com/lists/oss-security/2009/05/04/1
http://www.mandriva.com/security/advisories?name=MDVSA-2009:135
http://www.mandriva.com/security/advisories?name=MDVSA-2009:119
http://www.mandriva.com/security/advisories?name=MDVSA-2009:118
http://www.debian.org/security/2009/dsa-1800
http://secunia.com/advisories/35656
http://secunia.com/advisories/35121
http://patchwork.ozlabs.org/patch/25238/
http://lwn.net/Articles/331435/