pam_ldap is a Pluggable Authentication Module which allows authentication against LDAP directories.
Steve Rigler discovered that pam_ldap does not correctly handle "PasswordPolicyResponse" control responses from an LDAP directory. This causes the pam_authenticate() function to always succeed, even if the previous authentication failed.
A locked user may exploit this vulnerability to bypass the LDAP authentication mechanism, possibly gaining unauthorized access to the system.
There is no known workaround at this time.
All pam_ldap users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=sys-auth/pam_ldap-183"