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 htmlspecialchars function in PHP before 5.2.12 does not properly handle (1) overlong UTF-8 sequences, (2) invalid Shift_JIS sequences, and (3) invalid EUC-JP sequences, which allows remote attackers to conduct cross-site scripting (XSS) attacks by placing a crafted byte sequence before a special character.

PHP before 5.2.12 does not properly handle session data, which has unspecified impact and attack vectors related to (1) interrupt corruption of the SESSION superglobal array and (2) the session.save_path directive.

The tempnam function in ext/standard/file.c in PHP before 5.2.12 and 5.3.x before 5.3.1 allows context-dependent attackers to bypass safe_mode restrictions, and create files in group-writable or world-writable directories, via the dir and prefix arguments.

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 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.