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Security Bulletin: AIX is vulnerable to a privilege escalation vulnerability due to invscout (CVE-2022-36768)

Security Bulletin


Summary

A vulnerability in the AIX invscout command could allow a non-privileged local user to obtain root privileges (CVE-2022-36768).

Vulnerability Details

CVEID:   CVE-2022-36768
DESCRIPTION:   IBM AIX could allow a non-privileged local user to exploit a vulnerability in the invscout command to obtain root privileges.
CVSS Base score: 8.4
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/232014 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)
AIX 7.1
AIX 7.2
AIX 7.3
VIOS 3.1

The following fileset levels are vulnerable:

Fileset Lower Level Upper Level
invscout.rte 2.2.0.0 2.2.0.22

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 ftp or http from:
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 Level bos.rte.libc prereq
7.1 7.1.5.30
7.2 7.2.3.0
VIOS Level bos.rte.libc prereq
3.1 7.2.3.0
To extract the fixes from the tar file:
tar xvf invscout_fix3.tar
cd invscout_fix3
Verify you have retrieved the fixes intact:
The checksums below were generated using the "openssl dgst -sha256 [filename]" command as the following:
openssl dgst -sha256 filename
7a3ad189232a95fe99eb88fc6faf890ee2ae9076e863d31e4fa97c9835aeb32a invscout.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:
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

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References

Complete CVSS v3 Guide
On-line Calculator v3

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Related Information

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

AIX Security Bulletin (ASCII format)

Acknowledgement

The vulnerability was reported to IBM by Christer Oberg.

Change History

08 Sep 2022: 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

Review the IBM security bulletin disclaimer and definitions regarding your responsibilities for assessing potential impact of security vulnerabilities to your environment.

Document Location

Worldwide

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Document Information

Modified date:
07 October 2022

UID

ibm16619725

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