pam_ldap/nss_ldap fail to re-start TLS when following referred connections. This can result in credentials being sent in clear text when pam_ldap/nss_ldap attempt to rebind.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/38494/ldap.txt
Source: https://packetstormsecurity.com/files/38494/ldap.txt.html