Buffer overflow in the memnstr function in PHP 4.4.x before 4.4.9 and PHP 5.6 through 5.2.6 allows context-dependent attackers to cause a denial of service (crash) and possibly execute arbitrary code via the delimiter argument to the explode function. NOTE: the scope of this issue is limited since most applications would not use an attacker-controlled delimiter, but local attacks against safe_mode are feasible.
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.