FreeBSD 4.3/4.4 - Login Capabilities Privileged File Reading

                							

                source: http://www.securityfocus.com/bid/3344/info

FreeBSD is a freely available, open source implementation of the BSD UNIX Operating System. It is developed and maintained by the FreeBSD Project.

It is possible for a user with access to a system via SSH to gain access to privileged information. This problem is caused by a mixture of problems with login capabilities, the FreeBSD OpenSSH port not dropping privileges during part of the login process, and login not dropping privileges at the correct time. A user could make a malicious entry in the .login.conf file in their home directoy, and read files such as the master.passwd file and gain access to encrypted passwords on the system.

This issue does not appear to affect other BSD distributions. 

In a .login.conf entry contained in a home directory, make the following entry if accessing the system via OpenSSH:

default: :copyright=/etc/master.passwd:

or

:welcome=/etc/master.passwd:

Otherwise, if accessing the system via login, make the following entry in a .login.conf:

default: :nologin=/etc/master.passwd: