Multiple integer overflows in PHP 4 before 4.4.8, and PHP 5 before 5.2.4, allow remote attackers to obtain sensitive information (memory contents) or cause a denial of service (thread crash) via a large len value to the (1) strspn or (2) strcspn function, which triggers an out-of-bounds read. NOTE: this affects different product versions than CVE-2007-3996.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.