Security Bulletin: AIX is affected by a denial of service (CVE-2022-43680) due to Python

Summary

A vulnerability in Python could allow a remote attacker to cause a denial of service (CVE-2022-43680). Python is used by AIX as part of Ansible node management automation.

Vulnerability Details

CVEID:CVE-2022-43680
**DESCRIPTION:**libexpat is vulnerable to a denial of service, caused by a use-after free created by overeager destruction of a shared DTD in XML_ExternalEntityParserCreate in out-of-memory situations. A remote attacker could exploit this vulnerability to cause a denial of service.
CVSS Base score: 7.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/238951 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Affected Products and Versions

The following fileset levels are vulnerable:

Note:

A. Latest level of Python fileset is available from the web download site:

<https://www-01.ibm.com/marketing/iwm/iwm/web/pickUrxNew.do?source=aixbp&gt;

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

Example: lslpp -L | grep -i python3.9.base

Remediation/Fixes

FIXES

IBM strongly recommends addressing the vulnerability now.

A fix is available, and it can be downloaded from:

<https://www-01.ibm.com/marketing/iwm/iwm/web/pickUrxNew.do?source=aixbp&gt;

To extract the fixes from the tar file:

zcat python-3.9.14.1.tar.Z | tar xvf -

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

Note that all the previously reported security vulnerability fixes are also included in above mentioned fileset level.

To preview the fix installation:

installp -apYd . python3.9.base

To install the fix package:

installp -aXYd . python3.9.base

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:

<http://aix.software.ibm.com/aix/efixes/security/python_advisory3.asc.sig&gt;

<https://aix.software.ibm.com/aix/efixes/security/python_advisory3.asc.sig&gt;

ftp://aix.software.ibm.com/aix/efixes/security/python_advisory3.asc.sig

Workarounds and Mitigations

None