COMMAND
nslookup
SYSTEMS AFFECTED
AIX 4.1, 4.2
PROBLEM
The nslookup command has a vulnerability that allows local users
to become root. Here's the catch. If nslookup is installed with
the s-bit all users can create and overwrite files owned by root.
This works in the interactive mode, when dumping dns-records to a
file (with ls -d DOMAINNAME > FILE for example). This was tested
on aix 4.2.0, 4.2.1 and 4.1.1, where nslookup is installed
suid-root by default.
SOLUTION
This problem can be alleviated by removing the set-user-id bit
from the "nslookup" program. Removing the set-user-id bit will
not result in lost functionality unless /etc/resolv.conf exists
and is not world-readable. Official fix is:
AIX 4.1........... APAR - IX71464
AIX 4.2........... APAR - IX70815