The asn1_time_to_time_t function in ext/openssl/openssl.c in PHP before 5.3.28, 5.4.x before 5.4.23, and 5.5.x before 5.5.7 does not properly parse (1) notBefore and (2) notAfter timestamps in X.509 certificates, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted certificate that is not properly handled by the openssl_x509_parse function.

Session fixation vulnerability in the Sessions subsystem in PHP before 5.5.2 allows remote attackers to hijack web sessions by specifying a session ID.

ext/xml/xml.c in PHP before 5.3.27 does not properly consider parsing depth, which allows remote attackers to cause a denial of service (heap memory corruption) or possibly have unspecified other impact via a crafted document that is processed by the xml_parse_into_struct function.