There is a vulnerability in the lscore command that affects AIX.,There is a vulnerability in the lscore command that affects VIOS.

IBM SECURITY ADVISORY

First Issued: Mon Jan 10 13:18:02 CST 2022

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

Security Bulletin: Vulnerability in lscore affects AIX (CVE-2021-38991)

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

SUMMARY:

There is a vulnerability in the lscore command that affects AIX.

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

VULNERABILITY DETAILS:

CVEID: CVE-2021-38991
    https://vulners.com/cve/CVE-2021-38991
    https://vulners.com/cve/CVE-2021-38991
DESCRIPTION: IBM AIX could allow a non-privileged local user to exploit a
    vulnerability in the lscore command which could lead to code
    execution.
CVSS Base Score: 8.4
CVSS Temporal Score: See 
    https://exchange.xforce.ibmcloud.com/vulnerabilities/212953
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)


AFFECTED PRODUCTS AND VERSIONS:

    AIX 7.1, 7.2, 7.3
    VIOS 3.1

    The vulnerabilities in the following filesets are being addressed:
    
    key_fileset = aix

    Fileset                 Lower Level  Upper Level KEY 
    ---------------------------------------------------------
    bos.rte.security        7.1.5.0      7.1.5.37    key_w_fs
    bos.rte.security        7.2.4.0      7.2.4.3     key_w_fs
    bos.rte.security        7.2.5.0      7.2.5.1     key_w_fs
    bos.rte.security        7.2.5.100    7.2.5.101   key_w_fs
    bos.rte.security        7.3.0.0      7.3.0.0     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.security


REMEDIATION:

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

        AIX Level APAR     Availability  SP        KEY
        -----------------------------------------------------
        7.1.5     IJ36805  **            SP10      key_w_apar
        7.2.4     IJ36806  **            SP06      key_w_apar
        7.2.5     IJ36810  **            SP04      key_w_apar
        7.3.0     IJ36816  **            SP02      key_w_apar

        VIOS Level APAR    Availability  SP       KEY
        ----------------------------------------------------
        3.1.1      IJ36806 **            3.1.1.60 key_w_apar
        3.1.2      IJ36815 **            3.1.2.40 key_w_apar
        3.1.3      IJ36810 **            3.1.3.20 key_w_apar

        Subscribe to the APARs here:

        http://www.ibm.com/support/pages/apar/IJ36805
        http://www.ibm.com/support/pages/apar/IJ36806
        http://www.ibm.com/support/pages/apar/IJ36810
        http://www.ibm.com/support/pages/apar/IJ36815
        http://www.ibm.com/support/pages/apar/IJ36816

        https://www.ibm.com/support/pages/apar/IJ36805
        https://www.ibm.com/support/pages/apar/IJ36806
        https://www.ibm.com/support/pages/apar/IJ36810
        https://www.ibm.com/support/pages/apar/IJ36815
        https://www.ibm.com/support/pages/apar/IJ36816

        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

        AIX and VIOS fixes are available.

        The AIX and VIOS fixes can be downloaded via ftp or http from:

        ftp://aix.software.ibm.com/aix/efixes/security/lscore_fix.tar
        http://aix.software.ibm.com/aix/efixes/security/lscore_fix.tar
        https://aix.software.ibm.com/aix/efixes/security/lscore_fix.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
        ----------------------------------------------
        7.1.5.7    IJ36805s9a.211217.epkg.Z  key_w_fix
        7.1.5.8    IJ36805s9a.211217.epkg.Z  key_w_fix
        7.1.5.9    IJ36805s9a.211217.epkg.Z  key_w_fix
        7.2.4.2    IJ36806s2a.211217.epkg.Z  key_w_fix
        7.2.4.3    IJ36806s4a.211217.epkg.Z  key_w_fix
        7.2.4.4    IJ36806s4a.211217.epkg.Z  key_w_fix
        7.2.5.1    IJ36815s2a.211217.epkg.Z  key_w_fix
        7.2.5.2    IJ36815s2a.211217.epkg.Z  key_w_fix
        7.2.5.3    IJ36810s3a.211217.epkg.Z  key_w_fix
        7.3.0.1    IJ36816s1a.211217.epkg.Z  key_w_fix

        Please note that the above table refers to AIX TL/SP level as
        opposed to fileset level, i.e., 7.2.5.2 is AIX 7200-05-02.


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

        VIOS Level  Interim Fix (*.Z)         KEY
        -----------------------------------------------
        3.1.1.21    IJ36806s2a.211217.epkg.Z  key_w_fix
        3.1.1.25    IJ36806s2a.211217.epkg.Z  key_w_fix
        3.1.1.30    IJ36806s4a.211217.epkg.Z  key_w_fix
        3.1.1.40    IJ36806s4a.211217.epkg.Z  key_w_fix
        3.1.2.10    IJ36815s2a.211217.epkg.Z  key_w_fix
        3.1.2.21    IJ36815s2a.211217.epkg.Z  key_w_fix
        3.1.3.10    IJ36810s3a.211217.epkg.Z  key_w_fix
        3.1.3.14    IJ36810s3a.211217.epkg.Z  key_w_fix


        To extract the fixes from the tar file:

        tar xvf lscore_fix.tar
        cd lscore_fix

        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
        -----------------------------------------------------------------------------------------------------
        866141e4fcc92ecbfff15e3c216347f8788a84bba558647b53256acdf338c4dd  IJ36805s9a.211217.epkg.Z key_w_csum
        8be118a07a65509c99d09c7cd0b8e55f9eb192a0ceff7f73beb973031f405515  IJ36806s2a.211217.epkg.Z key_w_csum
        870448503c15caabb138e93d4d7e32348af51f8ef4db0cf35047876a5da0f68a  IJ36806s4a.211217.epkg.Z key_w_csum
        c8cf7f12d62220e44d22360cfc408bb6e3d090c3401429cddb4a4bf1e6c5160e  IJ36810s3a.211217.epkg.Z key_w_csum
        428938e255b869354fbd4e43f007b4e7224cdeb43d9ec1cc7cfecbfb18a244cc  IJ36815s2a.211217.epkg.Z key_w_csum
        eb681a0a23855b1805b6d5d111f5bb50faf318221b29e9af016ae3d410d9efa8  IJ36816s1a.211217.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:

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

        http://www14.software.ibm.com/webapp/set2/sas/f/aix.efixmgmt/home.html

        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

To view previously issued advisories, please visit:

    http://www14.software.ibm.com/webapp/set2/subscriptions/onvdq

Contact IBM Support for questions related to this announcement:

    http://ibm.com/support/
    https://ibm.com/support/

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

    Download the key from our web page:

ftp://ftp.software.ibm.com/systems/power/AIX/systems_p_os_aix_security_pubkey.txt

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: Vulnerability in lscore affects AIX (CVE-2021-38991)
    https://www.ibm.com/support/pages/node/6538952

ACKNOWLEDGEMENTS:

None.

CHANGE HISTORY:

First Issued: Mon Jan 10 13:18:02 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.