Vulnerability in passwd for HP-UX 11.00 and 11.11 allows local users to corrupt the password file and cause a denial of service.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5518
http://www.securityfocus.com/bid/4582
http://www.kb.cert.org/vuls/id/977779
http://www.iss.net/security_center/static/8939.php