Hash: SHA1

             AUSCERT External Security Bulletin Redistribution

                  ESB-2005.0445 -- IBM SECURITY ADVISORY
             Buffer overflow vulnerability in penable command
                               14 June 2005


        AusCERT Security Bulletin Summary

Product:           penable
Publisher:         IBM
Operating System:  AIX 5.3
                   AIX 5.2
                   AIX 5.1
Impact:            Root Compromise
Access:            Existing Account

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Hash: SHA1


First Issued:  Fri Jun 10 13:12:27 CDT 2005

                           VULNERABILITY SUMMARY

VULNERABILITY:      A buffer overflow vulnerability in the penable command
                    may allow any local user in the system group to gain
                    root privileges.

PLATFORMS:          AIX 5.1, 5.2 and 5.3.

SOLUTION:           Apply the workaround as described below.

THREAT:             A local user in the system group may gain root

CERT VU Number:     N/A
CVE Number:         N/A
                           DETAILED INFORMATION

I.  Description

A vulnerability was discovered in the penable command that allows a
local user in the system group to gain root privileges. Exploits for this
vulnerability may be publicly available. penable is one of six hard links.
The other hard links are pdisable, pstart, phold, pdelay and pshare. These
commands are used to perform various port management functions.

The command affected by this issue ships as part of the bos.rte.control
fileset. To determine if this fileset is installed, execute the following

# lslpp -w /usr/sbin/penable

If the fileset is installed it will be listed along with its version
information, state, type and a description.

II. Impact

A local user in the system group may exploit this buffer overflow
vulnerability to gain root privileges.

III.  Solutions

A. APARs and interim fixes

APARs and interim fixes will be provided. An updated advisory will be
published when these fixes are available.

B. Workaround

Setting the file mode bits to 500 will allow only the root user to execute
this command. This can be done by executing the following command as root:

# chmod 500 /usr/sbin/penable

Since penable, pdisable, pstart, phold, pdelay and pshare are hard links to
the same file, they will all be affected by this change.

Verify that the file mode bits have been updated:

# ls -la /usr/sbin/penable   
- - -r-x------   6 root     system        19366 May 16 14:30 /usr/sbin/penable

IV. Obtaining Fixes

AIX Version 5 APARs can be downloaded from:


Security related Interim Fixes can be downloaded from:


V.  Contact Information

If you would like to receive AIX Security Advisories via email, please


Comments regarding the content of this announcement can be directed to:


To request the PGP public key that can be used to communicate securely
with the AIX Security Team send email to security-alert@austin.ibm.com
with a subject of "get key". The key can also be downloaded from a PGP
Public Key Server. The key id is 0x9391C1F2.

Please contact your local IBM AIX support center for any assistance.

eServer is a trademark of International Business Machines Corporation.
IBM, AIX and pSeries are registered trademarks of International Business
Machines Corporation. All other trademarks are property of their respective
Version: GnuPG v1.4.1 (GNU/Linux)


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