PHP before 5.2.1 allows attackers to bypass safe_mode and open_basedir restrictions via unspecified vectors in the session extension. NOTE: it is possible that this issue is a duplicate of CVE-2006-6383.
http://www.vupen.com/english/advisories/2007/0546
http://www.trustix.org/errata/2007/0009/
http://www.securityfocus.com/bid/22496
http://www.php.net/releases/5_2_1.php
http://www.php.net/ChangeLog-5.php#5.2.1
http://www.openpkg.com/security/advisories/OpenPKG-SA-2007.010.html
http://secunia.com/advisories/24419