IBM AIX nslookup fails to drop root privileges

Overview

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

Description

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.

---

Impact

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

---

Solution

**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

---

Vendor Information

18419

Filter by status: All Affected Not Affected Unknown

Filter by content: __ Additional information available

__ Sort by: Status Alphabetical

Expand all

Javascript is disabled. Click here to view vendors.

IBM Affected

Updated: September 26, 2001

Status

Affected

Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

The CERT/CC has no additional comments at this time.

If you have feedback, comments, or additional information about this vulnerability, please send us [email](<mailto:[email protected]?Subject=VU%2318419 Feedback>).

CVSS Metrics

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

References

• <http://xforce.iss.net/static/604.php&gt;
• http://groups.google.com/groups?q=ERS-SVA-E01-1997:008.1&hl=en&rnum=3&selm=6383r7%24kts%243%40watnews1.watson.ibm.com

Acknowledgements

This document was written by Cory F. Cohen.

Other Information

CVE IDs:	CVE-1999-0093
Severity Metric:	2.76 Date Public: