During the development of the Hardening-Patch which adds security hardening features to the PHP codebase, several vulnerabilities within PHP were discovered. This advisory describes one of these flaws concerning a weakness in the implementation of the parse_str() function. Under certain conditions triggering the memory_limit request shutdown during a parse_str() call will result in the core of PHP believing that the register_globals directive is turned on (for the rest of the lifetime of the involved webserver process). This may allow an attacker to exploit security flaws in PHP applications that exist due to uninitialized global variables. Affected versions are PHP4 versions 4.4.0 and below and PHP5 versions 5.0.5 and below.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/41094/advisory_192005.78.txt
Source: https://packetstormsecurity.com/files/41094/Hardened-PHP-Project-Security-Advisory-2005-19.78.html