ftpd.c in (1) wu-ftpd 2.4.2 and (2) ftpd in HP HP-UX B.11.11 assigns uid 0 to the FTP client in certain operating-system misconfigurations in which PAM authentication can succeed even though no passwd entry is available for a user, which allows remote attackers to gain privileges, as demonstrated by a login attempt for an LDAP account when nsswitch.conf does not specify LDAP for passwd information.