useradd in shadow-utils before 4.0.3, and possibly other versions before 4.0.8, does not provide a required argument to the open function when creating a new user mailbox, which causes the mailbox to be created with unpredictable permissions and possibly allows attackers to read or modify the mailbox.

Unknown vulnerability in the passwd_check function in Shadow 4.0.4.1, and possibly other versions before 4.0.5, allows local users to conduct unauthorized activities when an error from a pam_chauthtok function call is not properly handled.