Vulnerability Note VU#18419

IBM AIX nslookup fails to drop root privileges

Original Release date: 26 Sep 2001 | Last revised: 27 Sep 2001


The nslookup command fails to drop privileges, allowing local attackers to gain root privileges.


The nslookup program fails to drop the privileges it gains from being setuid. This access appears to be needed to read the "/etc/resolv.conf" file. This problem was described in IBM ERS advisory ERS-SVA-E01-1997:008.1.


Intruders with access to a local user account may be able to gain root privileges.


Apply a Patch

For AIX version 4.1, system administrators should apply APAR #IX71464. For AIX version 4.2, system administrators should apply APAR #IX70815.

Disable the setuid bit on nslookup

You can prevent this vulnerability from being exploited by removing the setuid bit from the nslookup program. You can do this by executing the following command as root:

chmod 555 /usr/bin/nslookup

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
IBMAffected-26 Sep 2001
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



This document was written by Cory F. Cohen.

Other Information

  • CVE IDs: CVE-1999-0093
  • Date Public: 29 Oct 97
  • Date First Published: 26 Sep 2001
  • Date Last Updated: 27 Sep 2001
  • Severity Metric: 2.76
  • Document Revision: 10


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