prefs.php in SquirrelMail before 1.4.4, with register_globals enabled, allows remote attackers to inject local code into the SquirrelMail code via custom preference handlers.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9587
http://www.squirrelmail.org/security/issue/2005-01-14
http://www.redhat.com/support/errata/RHSA-2005-135.html
http://www.redhat.com/support/errata/RHSA-2005-099.html
http://www.gentoo.org/security/en/glsa/glsa-200501-39.xml
http://secunia.com/advisories/13962/
http://marc.info/?l=bugtraq&m=110702772714662&w=2
http://lists.apple.com/archives/security-announce/2005/Mar/msg00000.html