PHP 4.4.x before 4.4.9, and 5.x through 5.2.6, when used as a FastCGI module, allows remote attackers to cause a denial of service (crash) via a request with multiple dots preceding the extension, as demonstrated using foo..php.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.