The unserialize function in PHP 5.3.0 and earlier allows context-dependent attackers to cause a denial of service (resource consumption) via a deeply nested serialized variable, as demonstrated by a string beginning with a:1: followed by many {a:1: sequences.

The money_format function in PHP 5 before 5.2.4, and PHP 4 before 4.4.8, permits multiple (1) %i and (2) %n tokens, which has unknown impact and attack vectors, possibly related to a format string vulnerability.

The session_start function in ext/session in PHP 4.x up to 4.4.7 and 5.x up to 5.2.3 allows remote attackers to insert arbitrary attributes into the session cookie via special characters in a cookie that is obtained from (1) PATH_INFO, (2) the session_id function, and (3) the session_start function, which are not encoded or filtered when the new session cookie is generated, a related issue to CVE-2006-0207.

The parse_str function in (1) PHP, (2) Hardened-PHP, and (3) Suhosin, when called without a second parameter, might allow remote attackers to overwrite arbitrary variables by specifying variable names and values in the string to be parsed. NOTE: it is not clear whether this is a design limitation of the function or a bug in PHP, although it is likely to be regarded as a bug in Hardened-PHP and Suhosin.