The safe_mode implementation in PHP before 5.2.13 does not properly handle directory pathnames that lack a trailing / (slash) character, which allows context-dependent attackers to bypass intended access restrictions via vectors related to use of the tempnam function.
itrc.hp.com/service/cki/docDisplay.do?docId=emr_na-c02286083
lists.apple.com/archives/security-announce/2010//Aug/msg00003.html
secunia.com/advisories/38708
secunia.com/advisories/40551
securitytracker.com/id?1023661
support.apple.com/kb/HT4312
www.php.net/ChangeLog-5.php
www.php.net/releases/5_2_13.php
www.securityfocus.com/bid/38431
www.vupen.com/english/advisories/2010/0479
www.vupen.com/english/advisories/2010/1796