libuser before 0.57 uses a cleartext password value of (1) !! or (2) x for new LDAP user accounts, which makes it easier for remote attackers to obtain access by specifying one of these values.
https://fedorahosted.org/libuser/browser/NEWS?rev=libuser-0.57
https://exchange.xforce.ibmcloud.com/vulnerabilities/64677
http://www.vupen.com/english/advisories/2011/0226
http://www.vupen.com/english/advisories/2011/0201
http://www.vupen.com/english/advisories/2011/0184
http://www.securityfocus.com/bid/45791
http://www.redhat.com/support/errata/RHSA-2011-0170.html
http://www.mandriva.com/security/advisories?name=MDVSA-2011:019
http://securitytracker.com/id?1024960
http://secunia.com/advisories/43047
http://secunia.com/advisories/42966
http://secunia.com/advisories/42891
http://lists.fedoraproject.org/pipermail/package-announce/2011-January/053378.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-January/053365.html
http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10705