COMMAND
autofsd (automountd)
SYSTEMS AFFECTED
IRIX 6.2, 6.3, 6.4, 6.5, 6.5.1, AIX 4.3
PROBLEM
Following info is based on RSI Alert Advisory. It was discoverd
by Mark Zielinski. Autofsd is an RPC server which answers file
system mount and umount requests from the autofs file system. It
uses local files or name service maps to locate file systems to be
mounted. Users locally on the system can send requests to the
autofsd daemon and execute arbitrary commands as the superuser.
Note that this vulnerability may be reproduced as remote exploit
too.
Upon receiving a map argument from a client, the server will
attempt to verify if it is executable or not. If autofsd
determines the map has an executable flag, the server will append
the client's key and attempt to execute it. By sending a map name
that is executable on the server, and a key beginning with a
semicolon or a newline followed by a command, unprivileged users
can execute arbitrary commands as the superuser. The problem
occurs when the server appends the key to the map and attempts to
execute it by calling popen. Since popen executes the map and
key you specify by invoking a shell, it is possible to force it
into executing commands that were not meant to be executed.
To determine if the daemon is active on your system, run the
following command on AIX:
$ lssrc -s automountd
To disable the daemon until the fix can be applied (run as root):
# stopsrc -s automountd
SOLUTION
If you can't apply patch, diable autofs(1M) daemon by issuing:
chkconfig autofs off
and reboot. Apply following patches:
OS Version Vulnerable? Patch # Other Actions
---------- ----------- ------- -------------
IRIX 6.2 yes 3392 Note 1
IRIX 6.3 yes 3391 Note 1
IRIX 6.4 yes 3250 Note 1
IRIX 6.5 yes 6.5.2 Note 2
IRIX 6.5.1 yes 6.5.2 Note 2
IRIX 6.5.2 no Note 3
NOTES
1) This version of the IRIX operating system is in maintenance
mode and patches will no longer be produced when it retires.
Use workaround.
2) IRIX 6.5.2 needs to be installed to remove this vulnerability.
3) If you have not received an IRIX 6.5.2 CD for IRIX 6.5, contact
your SGI Support Provider or download the IRIX 6.5.2
Maintenance Release Stream from http://support.sgi.com/ or
ftp://patches.sgi.com/support/relstream/
Information about installing IRIX 6.5.2 can be found at:
http://support.sgi.com/6.5/installing.html
IBM is working on the following fixes which will be available
soon:
AIX 4.3.x: IX83752