There is a vulnerability in the AIX audit user commands for VIOS.,There is a vulnerability in the AIX audit user commands.

IBM SECURITY ADVISORY

First Issued: Mon Feb 28 16:34:28 CST 2022

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

Security Bulletin: Vulnerability in AIX audit commands (CVE-2021-38955)

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

SUMMARY:

There is a vulnerability in the AIX audit user commands.

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

VULNERABILITY DETAILS:

CVEID: CVE-2021-38955
    https://vulners.com/cve/CVE-2021-38955
    https://vulners.com/cve/CVE-2021-38955
DESCRIPTION: IBM AIX could allow a local user with elevated privileges to
    cause a denial of service due to a file creation vulnerability in the
    audit commands.
CVSS Base Score: 4.4
CVSS Temporal Score: See 
    https://exchange.xforce.ibmcloud.com/vulnerabilities/211825
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/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      7.2.4.4     key_w_fs
    bos.rte.security        7.2.5.0      7.2.5.2     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     IJ38113  **            SP10      key_w_apar
        7.2.4     IJ38115  **            SP06      key_w_apar
        7.2.5     IJ38117  **            SP04      key_w_apar
        7.3.0     IJ38121  **            SP02      key_w_apar

        VIOS Level APAR    Availability  SP       KEY
        ----------------------------------------------------
        3.1.1      IJ38115 **            3.1.1.60 key_w_apar
        3.1.2      IJ38119 **            3.1.2.40 key_w_apar
        3.1.3      IJ38117 **            3.1.3.20 key_w_apar

        Subscribe to the APARs here:

        http://www.ibm.com/support/pages/apar/IJ38113
        http://www.ibm.com/support/pages/apar/IJ38115
        http://www.ibm.com/support/pages/apar/IJ38117
        http://www.ibm.com/support/pages/apar/IJ38119
        http://www.ibm.com/support/pages/apar/IJ38121

        https://www.ibm.com/support/pages/apar/IJ38113
        https://www.ibm.com/support/pages/apar/IJ38115
        https://www.ibm.com/support/pages/apar/IJ38117
        https://www.ibm.com/support/pages/apar/IJ38119
        https://www.ibm.com/support/pages/apar/IJ38121

        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/audit_fix.tar
        http://aix.software.ibm.com/aix/efixes/security/audit_fix.tar
        https://aix.software.ibm.com/aix/efixes/security/audit_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    IJ38113m9a.220227.epkg.Z  key_w_fix
        7.1.5.8    IJ38113m9a.220227.epkg.Z  key_w_fix
        7.1.5.9    IJ38113m9a.220227.epkg.Z  key_w_fix
        7.2.4.3    IJ38115m5a.220227.epkg.Z  key_w_fix
        7.2.4.4    IJ38115m5a.220227.epkg.Z  key_w_fix
        7.2.4.5    IJ38115m5a.220227.epkg.Z  key_w_fix
        7.2.5.1    IJ38119m2a.220227.epkg.Z  key_w_fix
        7.2.5.2    IJ38119m2a.220227.epkg.Z  key_w_fix
        7.2.5.3    IJ38117m3a.220227.epkg.Z  key_w_fix
        7.3.0.1    IJ38121m1a.220227.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
        -----------------------------------------------
        3.1.1.30    IJ38115m5a.220227.epkg.Z  key_w_fix
        3.1.1.40    IJ38115m5a.220227.epkg.Z  key_w_fix
        3.1.1.50    IJ38115m5a.220227.epkg.Z  key_w_fix
        3.1.2.10    IJ38119m2a.220227.epkg.Z  key_w_fix
        3.1.2.21    IJ38119m2a.220227.epkg.Z  key_w_fix
        3.1.3.10    IJ38117m3a.220227.epkg.Z  key_w_fix
        3.1.3.14    IJ38117m3a.220227.epkg.Z  key_w_fix

        To extract the fixes from the tar file:

        tar xvf audit_fix.tar
        cd audit_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
        -----------------------------------------------------------------------------------------------------
        9c106a0fcc85c04f1cb41b939b3019daa7fb2fa2b826f6ea41bf4b6e415f54ae  IJ38113m9a.220227.epkg.Z key_w_csum
        3da452a1fadea25122c899a851907b8df6e0346f016373e22e98a36a7deedaf2  IJ38115m5a.220227.epkg.Z key_w_csum
        abcc517295ba08a79f994f1091778c7845729cb96a0ac5530b0777ea23e93050  IJ38117m3a.220227.epkg.Z key_w_csum
        851e4b2c602e5e869b36bea8190da813b880f10aae6227f2595ecf06289dd58c  IJ38119m2a.220227.epkg.Z key_w_csum
        e61fce4c31be526987ad5842155d71a8912622dde0b76091545ad3a40ea70f78  IJ38121m1a.220227.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/audit_advisory.asc.sig
        https://aix.software.ibm.com/aix/efixes/security/audit_advisory.asc.sig
        ftp://aix.software.ibm.com/aix/efixes/security/audit_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 AIX audit commands (CVE-2021-38955)
    https://www.ibm.com/support/pages/node/6560236

ACKNOWLEDGEMENTS:

None.

CHANGE HISTORY:

First Issued: Mon Feb 28 16:34:28 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.