The core server component in PostgreSQL 8.4 before 8.4.1, 8.3 before 8.3.8, and 8.2 before 8.2.14 allows remote authenticated users to cause a denial of service (backend shutdown) by "re-LOAD-ing" libraries from a certain plugins directory.
https://www.redhat.com/archives/fedora-package-announce/2009-September/msg00307.html
https://www.redhat.com/archives/fedora-package-announce/2009-September/msg00305.html
https://bugzilla.redhat.com/show_bug.cgi?id=522092
http://www.us.debian.org/security/2009/dsa-1900
http://www.ubuntu.com/usn/usn-834-1
http://www.securityfocus.com/bid/36314
http://www.securityfocus.com/archive/1/509917/100/0/threaded
http://www.postgresql.org/support/security.html
http://www.postgresql.org/docs/8.3/static/release-8-3-8.html
http://wiki.rpath.com/wiki/Advisories:rPSA-2010-0012
http://sunsolve.sun.com/search/document.do?assetkey=1-66-270408-1
http://secunia.com/advisories/36837
http://secunia.com/advisories/36800
http://secunia.com/advisories/36727
http://secunia.com/advisories/36660
http://marc.info/?l=bugtraq&m=134124585221119&w=2
http://lists.opensuse.org/opensuse-security-announce/2009-10/msg00004.html
http://lists.opensuse.org/opensuse-security-announce/2009-10/msg00001.html