nss-pam-ldapd before 0.7.18 and 0.8.x before 0.8.11 allows context-dependent attackers to cause a denial of service (application crash) and possibly execute arbitrary code by performing a name lookup on an application with a large number of open file descriptors, which triggers a stack-based buffer overflow related to incorrect use of the FD_SET macro.
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.