Heap-based buffer overflow in the php_quot_print_encode function in ext/standard/quot_print.c in PHP before 5.3.26 and 5.4.x before 5.4.16 allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via a crafted argument to the quoted_printable_encode function.
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.