Samba 3.x before 3.3.15, 3.4.x before 3.4.12, and 3.5.x before 3.5.7 does not perform range checks for file descriptors before use of the FD_SET macro, which allows remote attackers to cause a denial of service (stack memory corruption, and infinite loop or daemon crash) by opening a large number of files, related to (1) Winbind or (2) smbd.
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.