Hash: SHA1

             AUSCERT External Security Bulletin Redistribution

                          ESB-2005.0989 -- [AIX]
                 Buffer overflow vulnerability in muxatmd
                             16 December 2005


        AusCERT Security Bulletin Summary

Product:           muxatmd
Publisher:         IBM
Operating System:  AIX
Impact:            Root Compromise
Access:            Existing Account

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Hash: SHA1


First Issued: Thu Dec 15 09:00:44 CST 2005

                           VULNERABILITY SUMMARY

VULNERABILITY:      A buffer overflow vulnerability in muxatmd may allow
                    any local user to gain root privileges.

PLATFORMS:          AIX 5.1, 5.2 and 5.3.

SOLUTION:           Apply the APAR, interim fix or workaround as
                    described below.

THREAT:             A local user may gain root privileges.

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

I.  Description

A buffer overflow vulnerability in muxatmd may allow any local user to gain
root privileges.

The command affected by this issue ships as part of the
devices.common.IBM.atm.rte fileset. To determine if this fileset is
installed, execute the following command:

# lslpp -L devices.common.IBM.atm.rte

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

II. Impact

A local user may gain root privileges.

III.  Solutions

A. Official Fix

IBM provides the following fixes:

      APAR number for AIX 5.1.0: IY78221 (available approx. 01/30/06)
      APAR number for AIX 5.2.0: IY78222 (available approx. 01/30/06) 
      APAR number for AIX 5.3.0: IY78223 (available approx. 01/30/06)

NOTE: Affected customers are urged to upgrade to 5.1.0, 5.2.0 or 5.3.0 at
the latest maintenance level.

B. Interim Fix

Interim fixes are available for AIX 5.1.0, 5.2.0 and 5.3.0. The ifixes can
be downloaded via ftp from:


libisode_ifix.tar.Z is a compressed tarball containing this advisory,
ifix packages and cleartext PGP signatures for each ifix package.

Verify you have retrieved the fixes intact:
- - --------------------------------------------
The interim fixes below are named by using the APAR corresponding to the
release that the fix applies to. The APAR is followed by an underscore and
the maintenance level for the particular AIX release that a fix applies to.

The checksums below were generated using the "sum" and "md5sum" commands
and are as follows:

Filename                  sum           md5
IY78221_09.051109.epkg.Z  24042  1104   3b917ab19512e4613904a2222d0fac49  
IY78222_05.051028.epkg.Z  17112  1081   dcd99ad0e710d04520a6229b55abb731  
IY78222_06.051028.epkg.Z  03605  1082   e660aa65f81d9674b45c1de8f394684a  
IY78222_07.051028.epkg.Z  21113  1082   8d62c78ff3918f01f2937005a8413f23  
IY78223_01.051028.epkg.Z  37334  1108   f53f57ce4e33aa0fe9661af3a9ba2230  
IY78223_02.051028.epkg.Z  17692  1110   861f1ed6e37590ca872da2b31b1960f0  
IY78223_03.051028.epkg.Z  48165  1101   bd6f54ea569be551b9a34da445772b62  

These sums should match exactly. The PGP signatures in the compressed
tarball and on this advisory can also be used to verify the integrity of
the various files they correspond to. If the sums or signatures cannot be
confirmed, double check the command results and the download site
address. If those are OK, contact IBM AIX Security at
security-alert@austin.ibm.com and describe the discrepancy.

IMPORTANT: If possible, it is recommended that a mksysb backup of the
system is created. Verify it is both bootable, and readable before

These ifixes have not been fully regression tested; thus, IBM does not
warrant the fully correct functioning of the ifix.  Customers install the
ifix and operate the modified version of AIX at their own risk.

Interim Installation Instructions:
- - ----------------------------------
These packages use the new Interim Fix Management Solution to install
and manage ifixes. More information can be found at:


To preview an epkg ifix installation execute the following command:

# emgr -e ipkg_name -p       # where ipkg_name is the name of the
                             # ifix package being previewed.

To install an epkg ifix package, execute the following command:

# emgr -e ipkg_name -X       # where ipkg_name is the name of the
                             # ifix package being installed.

The "X" flag will expand any filesystems if required.

C. Workaround

Remote the setuid file mode bit
- - -------------------------------
Removing the setuid root file mode bit will prevent non-root users from
exploiting the vulnerability. To remove the setuid bit, execute the
following command:

# chmod 555 /usr/sbin/muxatmd

Verify that the file mode bits have been updated:

# ls -la /usr/sbin/muxatmd
- - -r-xr-xr-x   1 root     bin           62850 Apr 10 2005  /usr/sbin/muxatmd

muxatmd should be started by the root user to function normally.

IV. Obtaining Fixes

AIX Version 5 APARs can be downloaded from:


Security related Interim Fixes can be downloaded from:


V. Acknowledgments

This vulnerability was reported by David Litchfield of NGS Software. 

VI.  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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