session.c in the session extension in PHP before 5.2.13, and 5.3.1, does not properly interpret ; (semicolon) characters in the argument to the session_save_path function, which allows context-dependent attackers to bypass open_basedir and safe_mode restrictions via an argument that contains multiple ; characters in conjunction with a .. (dot dot).

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.

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 zend_restore_ini_entry_cb function in zend_ini.c in PHP 5.3.0, 5.2.10, and earlier versions allows context-specific attackers to obtain sensitive information (memory contents) and cause a PHP crash by using the ini_set function to declare a variable, then using the ini_restore function to restore the variable.

The proc_open function in ext/standard/proc_open.c in PHP before 5.2.11 and 5.3.x before 5.3.1 does not enforce the (1) safe_mode_allowed_env_vars and (2) safe_mode_protected_env_vars directives, which allows context-dependent attackers to execute programs with an arbitrary environment via the env parameter, as demonstrated by a crafted value of the LD_LIBRARY_PATH environment variable.

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.

Unspecified vulnerability in PHP before 5.2.11, and 5.3.x before 5.3.1, has unknown impact and attack vectors related to "missing sanity checks around exif processing."

Unspecified vulnerability in the imagecolortransparent function in PHP before 5.2.11 has unknown impact and attack vectors related to an incorrect "sanity check for the color index."

Cross-site scripting (XSS) vulnerability in index.php in Aardvark Topsites PHP 5.2.0 and earlier allows remote attackers to inject arbitrary web script or HTML via the q parameter in a search action. NOTE: it was later reported that 5.2.1 is also affected.

index.php in Aardvark Topsites PHP 5.2.0 and earlier allows remote attackers to obtain sensitive information via a nonexistent account name in the u parameter in a rate action, which reveals the installation path in an error message.