The Linear Congruential Generator (LCG) in PHP before 5.2.13 does not provide the expected entropy, which makes it easier for context-dependent attackers to guess values that were intended to be unpredictable, as demonstrated by session cookies generated by using the uniqid function.

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.

The resource system in PHP 5.0.0 through 5.2.1 allows context-dependent attackers to execute arbitrary code by interrupting the hash_update_file function via a userspace (1) error or (2) stream handler, which can then be used to destroy and modify internal resources. NOTE: it was later reported that PHP 5.2 through 5.2.13 and 5.3 through 5.3.2 are also affected.