AIX is vulnerable to privilege escalation (CVE-2024-27273)

IBM SECURITY ADVISORY

First Issued: Mon May 6 08:12:16 CDT 2024

The most recent version of this document is available here:
https://aix.software.ibm.com/aix/efixes/security/kernel_advisory7.asc

Security Bulletin: AIX is vulnerable to privilege escalation (CVE-2024-27273)

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

SUMMARY:

Vulnerability in the AIX kernel may lead to privilege escalation
(CVE-2024-27273).

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

VULNERABILITY DETAILS:

CVEID: CVE-2024-27273
    https://vulners.com/cve/CVE-2024-27273
DESCRIPTION: IBM AIX's Unix domain datagram socket implementation could
    potentially expose applications using Unix domain datagram sockets
    with SO_PEERID operation and may lead to privilege escalation.
CVSS Base Score: 8.1
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/284903
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/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 vulnerabilities in the following filesets are being addressed:
    
    key_fileset = aix

    Fileset                 Lower Level  Upper Level KEY 
    ---------------------------------------------------------
    bos.mp64                7.2.5.0      7.2.5.107   key_w_fs
    bos.mp64                7.2.5.200    7.2.5.205   key_w_fs
    bos.mp64                7.3.0.0      7.3.0.5     key_w_fs
    bos.mp64                7.3.1.0      7.3.1.4     key_w_fs
    bos.mp64                7.3.2.0      7.3.2.1     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.mp64


REMEDIATION:

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

        AIX Level APAR     Availability  SP        KEY
        -----------------------------------------------------
        7.2.5     IJ50910  **            SP08      key_w_apar
        7.3.0     IJ50936  **            N/A       key_w_apar
        7.3.1     IJ50935  **            SP04      key_w_apar
        7.3.2     IJ50934  **            SP02      key_w_apar

        VIOS Level APAR    Availability  SP        KEY
        -----------------------------------------------------
        3.1.3      IJ50937 **            N/A       key_w_apar
        3.1.4      IJ50910 **            3.1.4.40  key_w_apar
        4.1.0      IJ50934 **            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.

        An LPAR system reboot is required to complete the iFix installation,
        or Live Update may be used on AIX 7.2 and 7.3 to avoid a reboot.

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

        https://aix.software.ibm.com/aix/efixes/security/kernel_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
        ----------------------------------------------
        7.2.5.5    IJ50910m5a.240502.epkg.Z  key_w_fix
        7.2.5.6    IJ50910m6a.240502.epkg.Z  key_w_fix
        7.2.5.7    IJ50910s7a.240418.epkg.Z  key_w_fix
        7.3.0.2    IJ50936m2a.240502.epkg.Z  key_w_fix
        7.3.0.3    IJ50936m3a.240502.epkg.Z  key_w_fix
        7.3.0.4    IJ50936m4a.240502.epkg.Z  key_w_fix
        7.3.1.1    IJ50935m1a.240502.epkg.Z  key_w_fix
        7.3.1.2    IJ50935m2a.240502.epkg.Z  key_w_fix
        7.3.1.3    IJ50935s3a.240418.epkg.Z  key_w_fix
        7.3.2.1    IJ50934s1a.240418.epkg.Z  key_w_fix

        Please note that the above table refers to AIX TL/SP level as
        opposed to fileset level, i.e., 7.2.5.6 is AIX 7200-05-06.

        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    IJ50937m2a.240502.epkg.Z  key_w_fix
        3.1.3.30    IJ50937m3a.240502.epkg.Z  key_w_fix
        3.1.3.40    IJ50937m4a.240502.epkg.Z  key_w_fix
        3.1.4.10    IJ50910m5a.240502.epkg.Z  key_w_fix
        3.1.4.21    IJ50910m6a.240502.epkg.Z  key_w_fix
        3.1.4.31    IJ50910s7a.240418.epkg.Z  key_w_fix
        4.1.0.10    IJ50934s1a.240418.epkg.Z  key_w_fix


        The fixes are cumulative and address previously issued
        AIX/VIOS kernel security and HIPER bulletins with respect to SP
        and TL, which includes:
        https://aix.software.ibm.com/aix/efixes/security/kernel_advisory6.asc
        https://www.ibm.com/support/pages/node/7105282
        https://www.ibm.com/support/pages/node/6857545
        https://aix.software.ibm.com/aix/efixes/security/kernel_advisory5.asc
        https://www.ibm.com/support/pages/node/6847947

        To extract the fixes from the tar file:

        tar xvf kernel_fix7.tar
        cd kernel_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
        -----------------------------------------------------------------------------------------------------
        20e7f9984bd3f82f0edf2523e039476c35a9b5ee19ce642524205cc078f37df2  IJ50910m5a.240502.epkg.Z key_w_csum
        26ada723ea3ecde12c83b04a8f2266d518bbf282a8dcec8972b9947d46b1d341  IJ50910m6a.240502.epkg.Z key_w_csum
        6ce0cc7acef1e5cc4f27493e49d7d5687d1b111eaaf1bf161b88a41fe88f022f  IJ50910s7a.240418.epkg.Z key_w_csum
        e604f15538d68688dadff227c822c01c488884865b9d9a9c3567ce4f098b90ec  IJ50934s1a.240418.epkg.Z key_w_csum
        f7d5ecde8c0e146c164c65bc77ca3a15144d2132eeba269dd5ecb880a9e94734  IJ50935m1a.240502.epkg.Z key_w_csum
        cebad1156c081a9345374db95c8533799fcd7fe1c95f16faeb97f01fddda9946  IJ50935m2a.240502.epkg.Z key_w_csum
        fbc7cad5e854772fce7e5cd2426e7c653f6ae2cc9ecff3735c14c63a0c41c96d  IJ50935s3a.240418.epkg.Z key_w_csum
        953c8c96ed53f202a03c8c044d72e64b8778e6cd4a4e60dcd34ff904dcaa0c99  IJ50936m2a.240502.epkg.Z key_w_csum
        c97fb2d06e6efbca162134292e242aa5892c7bc3fbeae72b675ff8b6d4361c4a  IJ50936m3a.240502.epkg.Z key_w_csum
        691164620d96cb9e353aba78f5a8ca288ab625efca6bc536052b163b1f3c15e1  IJ50936m4a.240502.epkg.Z key_w_csum
        06709014779183f1a204228724aa439401b14d13c2a9d55300bf8d91d138754c  IJ50937m2a.240502.epkg.Z key_w_csum
        bf7e6ee7afdec2fa58662ce973fe4f7903446b20219463174d5bd4b3b031b40b  IJ50937m3a.240502.epkg.Z key_w_csum
        03d7ad9b0fc0dfad5862060140d1a5b926539c7e91fb9c6b157f2fc83a154ae9  IJ50937m4a.240502.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/kernel_advisory7.asc.sig

    C. FIX AND INTERIM FIX INSTALLATION

        An LPAR system reboot is required to complete the iFix installation,
        or Live Update may be used on AIX 7.2 and 7.3 to avoid a reboot.

        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/kernel_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 privilege escalation
(CVE-2024-27273)
    https://www.ibm.com/support/pages/node/7150297

ACKNOWLEDGEMENTS:

The vulnerability was reported to IBM by Christian Kohlschuetter.

CHANGE HISTORY:

First Issued: Mon May  6 08:12:16 CDT 2024

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

*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.