IBM Support

Security Bulletin: AIX is vulnerable to arbitrary command execution due to invscout (CVE-2023-28528)

Security Bulletin


Summary

A vulnerability in the AIX invscout command could allow a non-privileged local user to execute arbitrary commands (CVE-2023-28528).

Vulnerability Details

CVEID:   CVE-2023-28528
DESCRIPTION:   IBM AIX could allow a non-privileged local user to exploit a vulnerability in the invscout command to execute arbitrary commands.
CVSS Base score: 8.4
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/251207 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Affected Products and Versions

Affected Product(s)Version(s)
AIX7.1
AIX7.2
AIX7.3
VIOS3.1

 

The following fileset levels are vulnerable:

 

FilesetLower LevelUpper Level
invscout.rte2.2.0.02.2.0.23

 

To find out whether the affected filesets are installed on your systems, refer to the lslpp command found in AIX user's guide.

 

Example: lslpp -L | grep -i invscout.rte

 

Remediation/Fixes

A. FIXES

 

IBM strongly recommends addressing the vulnerability now.

 

AIX and VIOS fixes are available.

 

The AIX and VIOS fixes can be downloaded via https from:

https://aix.software.ibm.com/aix/efixes/security/invscout_fix4.tar

 

The link above is to a tar file containing this signed advisory, fix packages, and OpenSSL signatures for each package. The fixes below include prerequisite checking. This will enforce the correct mapping between the fixes and AIX Technology Levels.

 

For AIX 7.1, 7.2, and VIOS 3.1, you must be on the 'bos.rte.libc prereq' level before installing the new invscout.rte package.

 

AIX Levelbos.rte.libc prereq
7.17.1.5.30
7.27.2.3.0

 

VIOS Levelbos.rte.libc prereq
3.17.2.3.0

 

To extract the fixes from the tar file:

 

tar xvf invscout_fix4.tar

cd invscout_fix4

 

Verify you have retrieved the fixes intact:

The checksums below were generated using the "openssl dgst -sha256 [filename]" command as the following:

 

openssl dgst -sha256filename
f13845513b60d3df0699a30fa1c328079983a35ae4b6cfa6db4e4d571b2d530cinvscout.rte

 

These sums should match exactly. The OpenSSL signatures in the tar file and on this advisory can also be used to verify the integrity of the fixes. If the sums or signatures cannot be confirmed, contact IBM Support at http://ibm.com/support/ and describe the discrepancy. 

 

openssl dgst -sha256 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file]

openssl dgst -sha256 -verify [pubkey_file] -signature [ifix_file].sig [ifix_file]

 

Published advisory OpenSSL signature file location:

https://aix.software.ibm.com/aix/efixes/security/invscout_advisory4.asc.sig

 

B. FIX INSTALLATION

 

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

proceeding.

 

To preview the fix installation:

installp -apYd . invscout

 

To install the fix package:

installp -aXYd . invscout

 

Workarounds and Mitigations

None

Get Notified about Future Security Bulletins

References

Off

Acknowledgement

The vulnerability was reported to IBM by Tim Brown of Cisco Security Advisory EMEA

Change History

12 Apr 2023: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.

Document Location

Worldwide

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG10","label":"AIX"},"Component":"","Platform":[{"code":"PF002","label":"AIX"}],"Version":"7.1,7.2,7.3","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}}]

Document Information

Modified date:
24 April 2023

UID

ibm16983232