IBM SECURITY ADVISORY

First Issued: Fri Apr 25 08:23:03 CDT 2025
|Updated: Mon May  5 14:46:26 CDT 2025
|Update: New iFixes provided for AIX 7.2 TL5 SP7, 7.3 TL1 SP2 and SP3,
|   7.3 TL2 SP1, and VIOS 3.1.4.31. The new iFixes include a packaging 
|   change to clarify that the iFixes are cumulative and address relevant,
|   previously issued AIX/VIOS libxml2 security bulletins. There is no 
|   functional change. Both new and original iFixes address the current and
|   previously issued AIX/VIOS libxml2 security bulletins.

The most recent version of this document is available here:
https://aix.software.ibm.com/aix/efixes/security/libxml2_advisory7.asc

Security Bulletin: AIX is vulnerable to a denial of service due to libxml2
    (CVE-2022-49043)

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

SUMMARY:

    Vulnerability in libxml2 could allow a remote attacker to cause a denial
    of service (CVE-2022-49043). AIX uses libxml2 as part of its XML parsing
    functions.


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

VULNERABILITY DETAILS:

    CVEID: CVE-2022-49043
        https://www.cve.org/CVERecord?id=CVE-2022-49043
    DESCRIPTION: xmlXIncludeAddNode in xinclude.c in libxml2 before 2.11.0
        has a use-after-free.
    CVSS Base Score: 8.1
    CVSS Environmental Score*: Undefined
    CVSS Vector: (CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/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      7.2.5.204   key_w_fs
        bos.rte.control         7.3.1.0      7.3.1.3     key_w_fs
        bos.rte.control         7.3.2.0      7.3.2.2     key_w_fs
        bos.rte.control         7.3.3.0      7.3.3.0     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     IJ54061  **            SP10      key_w_apar
            7.3.1     IJ54257  **            N/A       key_w_apar
            7.3.2     IJ54258  **            SP04      key_w_apar
            7.3.3     IJ54059  **            SP01      key_w_apar

            VIOS Level APAR    Availability  SP        KEY
            -----------------------------------------------------
            3.1.4      IJ54061 **            3.1.4.60  key_w_apar
            4.1.0      IJ54258 **            4.1.0.40  key_w_apar
            4.1.1      IJ54059 **            4.1.1.10  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.

            The AIX and VIOS fixes can be downloaded via https from:
            https://aix.software.ibm.com/aix/efixes/security/libxml2_fix7.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
            ----------------------------------------------
|           7.2.5.7    IJ54061m7a.250505.epkg.Z  key_w_fix
            7.2.5.8    IJ54061s9a.250409.epkg.Z  key_w_fix
            7.2.5.9    IJ54061s9a.250409.epkg.Z  key_w_fix
|           7.3.1.2    IJ54257m3a.250505.epkg.Z  key_w_fix
|           7.3.1.3    IJ54257m3a.250505.epkg.Z  key_w_fix
            7.3.1.4    IJ54257s4a.250409.epkg.Z  key_w_fix
|           7.3.2.1    IJ54258m1a.250505.epkg.Z  key_w_fix
            7.3.2.2    IJ54258s3a.250409.epkg.Z  key_w_fix
            7.3.2.3    IJ54258s3a.250409.epkg.Z  key_w_fix
            7.3.3.0    IJ54059s0a.250409.epkg.Z  key_w_fix

            Please note that the above table refers to AIX TL/SP level as
            opposed to fileset level, i.e., 7.3.2.3 is AIX 7300-02-03.

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

            VIOS Level  Interim Fix (*.Z)         KEY
            -----------------------------------------------
|           3.1.4.31    IJ54061m7a.250505.epkg.Z  key_w_fix
            3.1.4.41    IJ54061s9a.250409.epkg.Z  key_w_fix
            3.1.4.50    IJ54061s9a.250409.epkg.Z  key_w_fix
            4.1.0.10    IJ54258s3a.250409.epkg.Z  key_w_fix
            4.1.0.21    IJ54258s3a.250409.epkg.Z  key_w_fix
            4.1.0.30    IJ54258s3a.250409.epkg.Z  key_w_fix
            4.1.1.0     IJ54059s0a.250409.epkg.Z  key_w_fix

            To extract the fixes from the tar file:

            tar xvf libxml2_fix7.tar
            cd libxml2_fix7

            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
            -----------------------------------------------------------------------------------------------------
            56dc4e356577beca93a26e51fb4ebc7a4999c29f364379449d34b483b109c16b  IJ54059s0a.250409.epkg.Z key_w_csum
            235b40168e231ae14445408127f2de17bcce9acbcb089b0516b891966cf999a7  IJ54061s9a.250409.epkg.Z key_w_csum
            54d57bc8ab645dd3aac686b732ca410bffafe7cbc867c5e7e1eb2d1ccefe80cd  IJ54257s4a.250409.epkg.Z key_w_csum
            0aab6c40bd3d42b53c81a58039836eae1d68fbd64c06a7a25df33221647a5171  IJ54258s3a.250409.epkg.Z key_w_csum
|           973d0a7ee66e88bdb267cb75e5074ba28bf95669c72eb6f4c29d3a61bc7a6402  IJ54061m7a.250505.epkg.Z key_w_csum
|           17b91cff749cc4b03245209a81c6c25a9b94b862e4aaf5289d3c66ff661616c1  IJ54257m3a.250505.epkg.Z key_w_csum
|           c5bd7e29697c4e52a02cff54493f3d28288b2ecd268ecf4ac60165239987f779  IJ54258m1a.250505.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_advisory7.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_advisory7.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-2022-49043)
        https://www.ibm.com/support/pages/node/7231815


ACKNOWLEDGEMENTS:

    None.


CHANGE HISTORY:

    First Issued: Fri Apr 25 08:23:03 CDT 2025
|   Updated: Mon May  5 14:46:26 CDT 2025
|   Update: New iFixes provided for AIX 7.2 TL5 SP7, 7.3 TL1 SP2 and SP3,
|       7.3 TL2 SP1, and VIOS 3.1.4.31. The new iFixes include a packaging 
|       change to clarify that the iFixes are cumulative and address relevant,
|       previously issued AIX/VIOS libxml2 security bulletins. There is no 
|       functional change. Both new and original iFixes address the current 
|       and previously issued AIX/VIOS libxml2 security bulletins.


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

*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.