PostgreSQL 8.3.x before 8.3.19, 8.4.x before 8.4.12, 9.0.x before 9.0.8, and 9.1.x before 9.1.4 allows remote authenticated users to cause a denial of service (server crash) by adding the (1) SECURITY DEFINER or (2) SET attributes to a procedural language's call handler.
http://www.postgresql.org/about/news/1398/
http://www.mandriva.com/security/advisories?name=MDVSA-2012:092
http://www.debian.org/security/2012/dsa-2491
http://secunia.com/advisories/50718
http://rhn.redhat.com/errata/RHSA-2012-1037.html
http://lists.opensuse.org/opensuse-updates/2012-10/msg00024.html
http://lists.opensuse.org/opensuse-updates/2012-10/msg00013.html
http://lists.opensuse.org/opensuse-updates/2012-09/msg00102.html
http://lists.fedoraproject.org/pipermail/package-announce/2012-June/082294.html
http://lists.fedoraproject.org/pipermail/package-announce/2012-June/082292.html
http://lists.fedoraproject.org/pipermail/package-announce/2012-June/082258.html