FreeBSD Asmon/Ascpu Vulnerability
BID:996
Info
FreeBSD Asmon/Ascpu Vulnerability
| Bugtraq ID: | 996 |
| Class: | Access Validation Error |
| CVE: |
CVE-2000-0163 |
| Remote: | No |
| Local: | Yes |
| Published: | Feb 19 2000 12:00AM |
| Updated: | Jul 11 2009 01:56AM |
| Credit: | This vulnerability was published in a FreeBSD Security Advisory, numbered SA-00:03.asmon, on February 19, 2000. |
| Vulnerable: |
FreeBSD FreeBSD 3.4 FreeBSD FreeBSD 3.3 FreeBSD FreeBSD 3.2 FreeBSD FreeBSD 3.1 FreeBSD FreeBSD 3.0 |
| Not Vulnerable: | |
Discussion
FreeBSD Asmon/Ascpu Vulnerability
A vulnerability exists in both the ascpu and asmon ports to FreeBSD. Ascpu and asmon are applets for the popular window manager AfterStep. They retain the look and feel of this window manager, and integrate well in to it's "dock" toolbar. As part of the port to FreeBSD, it was deemed necessary to give them access to /dev/kmem, necessitating them being installed setgid kmem. By passing a command line option, it is possible for an attacker to cause these applications to execute arbitrary commands with group 'kmem' privileges.
It should be noted that neither of these programs are truly part of FreeBSD. They are not part of any distribution of FreeBSD. Instead, they are part of the 'ports' section. The over 3000 packages included in ports are presented as-is, and in many cases have not been audited for security problems.
A vulnerability exists in both the ascpu and asmon ports to FreeBSD. Ascpu and asmon are applets for the popular window manager AfterStep. They retain the look and feel of this window manager, and integrate well in to it's "dock" toolbar. As part of the port to FreeBSD, it was deemed necessary to give them access to /dev/kmem, necessitating them being installed setgid kmem. By passing a command line option, it is possible for an attacker to cause these applications to execute arbitrary commands with group 'kmem' privileges.
It should be noted that neither of these programs are truly part of FreeBSD. They are not part of any distribution of FreeBSD. Instead, they are part of the 'ports' section. The over 3000 packages included in ports are presented as-is, and in many cases have not been audited for security problems.
Exploit / POC
FreeBSD Asmon/Ascpu Vulnerability
asmon -e "xterm"
asmon -e "xterm"
Solution / Fix
FreeBSD Asmon/Ascpu Vulnerability
Solution:
FreeBSD has released a new ports package for these applications. They can be downloaded from:
http://www.si.freebsd.org/es/ports/sysutils.html
or
ftp://ftp.freebsd.org/pub/FreeBSD/ports/packages/sysutils/asmon-0.60.tgz
ftp://ftp.freebsd.org/pub/FreeBSD/ports/packages/sysutils/ascpu-1.8.tgz
port skeletons are available at:
http://www.freebsd.org/ports/
Solution:
FreeBSD has released a new ports package for these applications. They can be downloaded from:
http://www.si.freebsd.org/es/ports/sysutils.html
or
ftp://ftp.freebsd.org/pub/FreeBSD/ports/packages/sysutils/asmon-0.60.tgz
ftp://ftp.freebsd.org/pub/FreeBSD/ports/packages/sysutils/ascpu-1.8.tgz
port skeletons are available at:
http://www.freebsd.org/ports/