AIX is vulnerable to a denial of service due to libxml2 (CVE-2024-25062)

IBM SECURITY ADVISORY

First Issued: Wed May 8 16:18:28 CDT 2024
|Updated: Tue Jun 4 15:20:02 CDT 2024
|Update: iFix added for VIOS 3.1.4.31.

The most recent version of this document is available here:
https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory6.asc

Security Bulletin: AIX is vulnerable to a denial of service due to libxml2
(CVE-2024-25062)

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

SUMMARY:

Vulnerability in libxml2 could allow a remote attacker to cause a denial
of service (CVE-2024-25062). AIX uses libxml2 as part of its XML parsing
functions.

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

VULNERABILITY DETAILS:

CVEID: CVE-2024-25062
    https://vulners.com/cve/CVE-2024-25062
DESCRIPTION: GNOME libxml2 is vulnerable to a denial of service, caused
    by a use-after-free flaw in the xmlValidatePopElement() function. By
    persuading a victim to open a specially crafted content, a remote
    attacker could exploit this vulnerability to cause the application to
    crash.
CVSS Base Score: 5.5
CVSS Temporal Score: See 
    https://exchange.xforce.ibmcloud.com/vulnerabilities/281615
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H)


AFFECTED PRODUCTS AND VERSIONS:

    AIX 7.2, 7.3
    VIOS 3.1, 4.1

    The following fileset levels are vulnerable:
    
    key_fileset = aix

    Fileset                 Lower Level  Upper Level KEY 
    ---------------------------------------------------------
    bos.rte.control         7.2.5.0      7.2.5.102   key_w_fs
    bos.rte.control         7.2.5.200    7.2.5.202   key_w_fs
    bos.rte.control         7.3.0.0      7.3.0.3     key_w_fs
    bos.rte.control         7.3.1.0      7.3.1.2     key_w_fs
    bos.rte.control         7.3.2.0      7.3.2.0     key_w_fs
    
    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 bos.rte.control


REMEDIATION:

    A. APARS
        
        IBM has assigned the following APARs to this problem:

        AIX Level APAR     Availability  SP        KEY
        -----------------------------------------------------
        7.2.5     IJ50602  **            SP08      key_w_apar
        7.3.0     IJ50827  **            N/A       key_w_apar
        7.3.1     IJ50635  **            SP04      key_w_apar
        7.3.2     IJ50601  **            SP02      key_w_apar

        VIOS Level APAR    Availability  SP        KEY
        -----------------------------------------------------
        3.1.3      IJ50828 **            N/A       key_w_apar
        3.1.4      IJ50602 **            3.1.4.40  key_w_apar
        4.1.0      IJ50601 **            4.1.0.20  key_w_apar

        Subscribe to the APARs here:

        https://www.ibm.com/support/pages/apar/[apar number]

        By subscribing, you will receive periodic email alerting you
        to the status of the APAR, and a link to download the fix once
        it becomes available.

    B. FIXES

        IBM strongly recommends addressing the vulnerability now.

        AIX and VIOS fixes are available. The fixes are cumulative and
        address previously issued AIX/VIOS libxml2 security bulletins with
        respect to SP and TL:
        https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory5.asc
        https://www.ibm.com/support/pages/node/7014485
        https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory4.asc
        https://www.ibm.com/support/pages/node/6953825
        https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory3.asc
        https://www.ibm.com/support/pages/node/6619729


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

        https://aix.software.ibm.com/aix/efixes/security/libxml2_fix6.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.

        AIX Level  Interim Fix (*.Z)         KEY
        ----------------------------------------------
        7.2.5.5    IJ50602m7a.240409.epkg.Z  key_w_fix
        7.2.5.6    IJ50602m7a.240409.epkg.Z  key_w_fix
        7.2.5.7    IJ50602m7a.240409.epkg.Z  key_w_fix
        7.3.0.2    IJ50827m4a.240409.epkg.Z  key_w_fix
        7.3.0.3    IJ50827m4a.240409.epkg.Z  key_w_fix
        7.3.0.4    IJ50827m4a.240409.epkg.Z  key_w_fix
        7.3.1.1    IJ50635m3a.240409.epkg.Z  key_w_fix
        7.3.1.2    IJ50635m3a.240409.epkg.Z  key_w_fix
        7.3.1.3    IJ50635m3a.240409.epkg.Z  key_w_fix
        7.3.2.1    IJ50601s1a.240409.epkg.Z  key_w_fix

        Please note that the above table refers to AIX TL/SP level as
        opposed to fileset level, i.e., 7.3.0.3 is AIX 7300-00-03.

        Please reference the Affected Products and Version section above
        for help with checking installed fileset levels.

        VIOS Level  Interim Fix (*.Z)         KEY
        -----------------------------------------------
        3.1.3.21    IJ50828m4a.240409.epkg.Z  key_w_fix
        3.1.3.30    IJ50828m4a.240409.epkg.Z  key_w_fix
        3.1.3.40    IJ50828m4a.240409.epkg.Z  key_w_fix

| 3.1.4.10 IJ50602m7a.240409.epkg.Z key_w_fix
3.1.4.21 IJ50602m7a.240409.epkg.Z key_w_fix
| 3.1.4.31 IJ50602m7a.240409.epkg.Z key_w_fix
4.1.0.10 IJ50601s1a.240409.epkg.Z key_w_fix

        To extract the fixes from the tar file:

        tar xvf libxml2_fix6.tar
        cd libxml2_fix6

        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                 KEY
        -----------------------------------------------------------------------------------------------------
        8bf16c8c98877439c134f7a21a326c60c2f5ba8633d2e23deb4801e64a073a4b  IJ50601s1a.240409.epkg.Z key_w_csum
        a921435fa369cd5fd6b96e8d2e3852ca1970e06d393f5467c8ca02b64e1141d6  IJ50602m7a.240409.epkg.Z key_w_csum
        c72a6348bf978e83a5c3a9d40fa0fe3f6f7a1cf95f70c99bd31085dda758ca99  IJ50635m3a.240409.epkg.Z key_w_csum
        d9d38426769f7fd01c46ff7c71576feef3cecdbcc2a50a590dd35b0112d90ab2  IJ50827m4a.240409.epkg.Z key_w_csum
        63353f135b6a41a5d8e35fd0873f032e378273453257b504be09ee20930f376f  IJ50828m4a.240409.epkg.Z key_w_csum

        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/libxml2_advisory6.asc.sig

    C. FIX AND INTERIM 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 a fix installation:

        installp -a -d fix_name -p all  # where fix_name is the name of the
                                        # fix package being previewed.
        To install a fix package:

        installp -a -d fix_name -X all  # where fix_name is the name of the
                                        # fix package being installed.

        Interim fixes have had limited functional and regression
        testing but not the full regression testing that takes place
        for Service Packs; however, IBM does fully support them.

        Interim fix management documentation can be found at:

        https://www.ibm.com/support/pages/managing-interim-fixes-aix

        To preview an interim fix installation:

        emgr -e ipkg_name -p         # where ipkg_name is the name of the
                                     # interim fix package being previewed.

        To install an interim fix package:

        emgr -e ipkg_name -X         # where ipkg_name is the name of the
                                     # interim fix package being installed.

WORKAROUNDS AND MITIGATIONS:

    None.

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

CONTACT US:

Note: Keywords labeled as KEY in this document are used for parsing
purposes.

If you would like to receive AIX Security Advisories via email,
please visit "My Notifications":

    http://www.ibm.com/support/mynotifications

Contact IBM Support for questions related to this announcement:

    https://ibm.com/support/

For information on how to securely verify AIX security bulletins and fixes:

    https://www.ibm.com/support/pages/node/6985269

To obtain the OpenSSL public key that can be used to verify the
signed advisories and ifixes:

    Download the key from our web page:

https://aix.software.ibm.com/aix/efixes/security/systems_p_os_aix_security_pubkey.txt

To verify the AIX/VIOS security bulletin:

    Published advisory OpenSSL signature file location:

    https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory6.asc.sig

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

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

REFERENCES:

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

RELATED INFORMATION:

IBM Secure Engineering Web Portal
    http://www.ibm.com/security/secure-engineering/bulletins.html

IBM Product Security Incident Response Blog
    https://www.ibm.com/blogs/psirt/

Security Bulletin: AIX is vulnerable to a denial of service due to
    libxml2 (CVE-2024-25062)
    https://www.ibm.com/support/pages/node/7150641

ACKNOWLEDGEMENTS:

None.

CHANGE HISTORY:

First Issued: Wed May  8 16:18:28 CDT 2024

| Updated: Tue Jun 4 15:20:02 CDT 2024
| Update: iFix added for VIOS 3.1.4.31.

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

*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.