The php_openssl_apply_verification_policy function in PHP before 5.2.11 does not properly perform certificate validation, which has unknown impact and attack vectors, probably related to an ability to spoof certificates.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A7394
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10438
https://exchange.xforce.ibmcloud.com/vulnerabilities/53334
http://www.vupen.com/english/advisories/2009/3184
http://www.securitytracker.com/id?1022914
http://www.php.net/releases/5_2_11.php
http://www.php.net/ChangeLog-5.php#5.2.11
http://www.debian.org/security/2009/dsa-1940
http://support.apple.com/kb/HT3937
http://secunia.com/advisories/40262
http://secunia.com/advisories/37482
http://secunia.com/advisories/36791
http://marc.info/?l=bugtraq&m=130497311408250&w=2
http://marc.info/?l=bugtraq&m=127680701405735&w=2
http://lists.opensuse.org/opensuse-security-announce/2009-10/msg00004.html
http://lists.apple.com/archives/security-announce/2009/Nov/msg00000.html