It has been discovered that libpam-ldap, the Pluggable Authentication Module allowing LDAP interfaces, ignores the result of an attempt to authenticate against an LDAP server that does not set an optional data field.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/39615/dsa-785-1.txt
Source: https://packetstormsecurity.com/files/39615/Debian-Linux-Security-Advisory-785-1.html