Buffer overflows in the (1) TZ and (2) SET TIME ZONE enivronment variables for PostgreSQL 7.2.1 and earlier allow local users to cause a denial of service and possibly execute arbitrary code.
http://www.redhat.com/support/errata/RHSA-2003-001.html
http://www.mandriva.com/security/advisories?name=MDKSA-2002:062
http://www.debian.org/security/2002/dsa-165
http://secunia.com/advisories/8034
http://marc.info/?l=bugtraq&m=103036987114437&w=2
http://marc.info/?l=bugtraq&m=103021186622725&w=2
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000524
http://archives.postgresql.org/pgsql-announce/2002-08/msg00004.php