AIX is affected by a denial of service due to Python

IBM SECURITY ADVISORY

First Issued: Thu Dec 22 10:15:28 CST 2022

The most recent version of this document is available here:

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

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
    https://vulners.com/cve/CVE-2022-43680
    https://vulners.com/cve/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 Environmental Score*: Undefined
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:

    AIX 7.3

    The following fileset levels are vulnerable:
    
    key_fileset = osrcaix

    Fileset          Lower Level   Upper Level    KEY
    ------------------------------------------------------
    python3.9.base   3.9.0.0       3.9.14.0       key_w_fs

    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

    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

        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

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



WORKAROUNDS AND MITIGATIONS:

    None.

===============================================================================

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    Download the key from our web page:

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Please contact your local IBM AIX support center for any
assistance.

REFERENCES:

Complete CVSS v3 Guide:
    http://www.first.org/cvss/user-guide
    https://www.first.org/cvss/user-guide
On-line Calculator v3:
    http://www.first.org/cvss/calculator/3.0
    https://www.first.org/cvss/calculator/3.0

RELATED INFORMATION:

Security Bulletin: AIX is affected by a denial of service (CVE-2022-43680)
    due to Python
    https://www.ibm.com/support/pages/node/6851439

ACKNOWLEDGEMENTS:

None.

CHANGE HISTORY:

First Issued: Thu Dec 22 10:15:28 CST 2022

===============================================================================

*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.