The process_bin_delete function in memcached.c in memcached 1.4.4 and other versions before 1.4.17, when running in verbose mode, allows remote attackers to cause a denial of service (segmentation fault) via a request to delete a key, which does not account for the lack of a null terminator in the key and triggers a buffer over-read when printing to stderr.
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.