Security Bulletin: AIX is affected by a denial of service (CVE-2023-45167) and a security restrictions bypass (CVE-2023-40217) due to Python

Summary

A vulnerability in Python could allow a non-privileged local user to cause a denial of service (CVE-2023-45167) and a remote attacker to cause a security restrictions bypass (CVE-2023-40217). Python is used by AIX as part of Ansible node management automation.

Vulnerability Details

CVEID:CVE-2023-45167
**DESCRIPTION:**IBM AIX’s Python implementation could allow a non-privileged local user to exploit a vulnerability to cause a denial of service.
CVSS Base score: 6.2
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/267965 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID:CVE-2023-40217
**DESCRIPTION:**Python could allow a remote attacker to bypass security restrictions, caused by a race condition in the SSLSocket module. When the socket is closed before the TLS handshake is complete, the data is treated as if it had been encrypted by TLS. An attacker could exploit this vulnerability to bypass the TLS handshake and inject a malicious client certificate into the connection and gain access to the server’s resources without being authenticated.
CVSS Base score: 7.4
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/264374 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N)

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.ibm.com/resources/mrs/assets?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.ibm.com/resources/mrs/assets?source=aixbp&gt;

To extract the fixes from the tar file:

zcat python-3.9.18.0.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:

<https://aix.software.ibm.com/aix/efixes/security/python_advisory6.asc.sig&gt;

Workarounds and Mitigations

None