The Zend Engine in PHP 4.x before 4.4.7, and 5.x before 5.2.2, allows remote attackers to cause a denial of service (stack exhaustion and PHP crash) via deeply nested arrays, which trigger deep recursion in the variable destruction routines.
http://www.ubuntu.com/usn/usn-549-2
http://www.php.net/releases/5_2_4.php
http://www.php.net/releases/4_4_8.php
http://www.php.net/ChangeLog-5.php#5.2.4
http://www.php.net/ChangeLog-4.php
http://www.mandriva.com/security/advisories?name=MDKSA-2007:090
http://www.mandriva.com/security/advisories?name=MDKSA-2007:089
http://www.mandriva.com/security/advisories?name=MDKSA-2007:088
http://www.mandriva.com/security/advisories?name=MDKSA-2007:087
http://us2.php.net/releases/5_2_2.php
http://us2.php.net/releases/4_4_7.php
http://security.gentoo.org/glsa/glsa-200705-19.xml
http://rhn.redhat.com/errata/RHSA-2007-0155.html
http://rhn.redhat.com/errata/RHSA-2007-0154.html
http://lists.opensuse.org/opensuse-security-announce/2007-07/msg00006.html