AIX is vulnerable to a denial of service (CVE-2023-5678 CVE-2023-6129 CVE-2023-6237) and an attacker may obtain sensitive information (CVE-2023-5363) due to OpenSSL

IBM SECURITY ADVISORY

First Issued: Thu Jan 25 14:11:09 CST 2024

The most recent version of this document is available here:

https://aix.software.ibm.com/aix/efixes/security/openssl_advisory40.asc

Security Bulletin: AIX is vulnerable to a denial of service (CVE-2023-5678,
CVE-2023-6129, CVE-2023-6237) and an attacker may obtain sensitive
information (CVE-2023-5363) due to OpenSSL

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

SUMMARY:

Vulnerabilities in OpenSSL could allow a remote attacker to cause a denial
of service (CVE-2023-5678, CVE-2023-6129, CVE-2023-6237) or obtain
sensitive information (CVE-2023-5363). OpenSSL is used by AIX as part of
AIX's secure network communications.

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

VULNERABILITY DETAILS:

CVEID: CVE-2023-5363
    https://vulners.com/cve/CVE-2023-5363
DESCRIPTION: OpenSSL could allow a remote attacker to obtain sensitive
    information, caused by an incorrect cipher key and IV length
    processing during the initialisation of some symmetric ciphers. By
    sending a specially crafted request, an attacker could exploit this
    vulnerability to obtain sensitive information, and use this
    information to launch further attacks against the affected system.
CVSS Base Score: 5.9
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/269418
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector:(CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)

CVEID: CVE-2023-5678
    https://vulners.com/cve/CVE-2023-5678
DESCRIPTION: Openssl is vulnerable to a denial of service, caused by a
    flaw when using DH_generate_key() function to generate an X9.42 DH
    key. By sending a specially crafted request, a remote attacker could
    exploit this vulnerability to cause a denial of service condition.
CVSS Base Score: 3.7
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/270771
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector:(CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L)

CVEID: CVE-2023-6129
    https://vulners.com/cve/CVE-2023-6129
DESCRIPTION: OpenSSL is vulnerable to a denial of service, caused by a
    flaw in the POLY1305 MAC (message authentication code) implementation.
    By sending a specially crafted request, a remote attacker could
    exploit this vulnerability to cause a denial of service condition.
CVSS Base Score: 5.9
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/278934
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector:(CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID: CVE-2023-6237
    https://vulners.com/cve/CVE-2023-6237
DESCRIPTION: OpenSSL is vulnerable to a denial of service, caused by a
    flaw in the handling of RSA public keys by the EVP_PKEY_public_check()
    function. By persuading a victim to sue a specially crafted RSA public
    keys for verification, a remote attacker could exploit this
    vulnerability to cause long delays, and results in a denial of service
    condition.
CVSS Base Score: 3.1
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/279450
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector:(CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L)


AFFECTED PRODUCTS AND VERSIONS:

    AIX 7.2, 7.3
    VIOS 3.1, 4.1

    The following fileset levels are vulnerable:
    
    key_fileset = osrcaix

    Fileset         Lower Level    Upper Level    KEY
    ------------------------------------------------------
    openssl.base    1.0.2.500      1.0.2.2107     key_w_fs
    openssl.base    1.1.1.0        1.1.1.2200     key_w_fs
    openssl.base    1.1.2.0        1.1.2.2200     key_w_fs
    openssl.base    20.13.102.1000 20.16.102.2108 key_w_fs
    openssl.base    3.0.0.0        3.0.10.1002    key_w_fs

    Note:
    A. 0.9.8, 1.0.1 OpenSSL versions are out-of-support. Support for
        OpenSSL 1.0.2 version ended in December 2023. Customers are
        advised to upgrade to OpenSSL 1.1.1 or 3.0 version.

    B. Latest level of OpenSSL fileset is available from the web download
        site:
        https://www.ibm.com/resources/mrs/assets?source=aixbp&S_PKG=openssl

    C. CVE-2023-5363, CVE-2023-6129, and CVE-2023-6237 only apply to 
        OpenSSL 3.0 version.

    To find out whether the affected filesets are installed on your systems,
    refer to the lslpp command found in the AIX user's guide.

    Example:  lslpp -L | grep -i openssl.base


REMEDIATION:

    A. FIXES

        IBM strongly recommends addressing the vulnerability now.

        The fixes can be downloaded via ftp or http from:

        https://aix.software.ibm.com/aix/efixes/security/openssl_fix40.tar

        The links above are 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.
        
        Note that the tar file contains Interim fixes that are based on
        OpenSSL version, and AIX OpenSSL fixes are cumulative. If an
        OpenSSL fileset with VMRF higher than the affected level listed
        above is available from the web download site, then that fileset
        is the recommended remediation. The OpenSSL 1.0.2 version shared
        objects provided in the library of OpenSSL 1.1.1 version is
        remediated.

        Applying the fix addresses all OpenSSL vulnerabilities reported
        up to and including community OpenSSL versions 1.0.2zj, 1.1.1x,
        and 3.0.13.

        You must be on the 'prereq for installation' level before
        applying the interim fix. This may require installing a new
        level(prereq version) first.


        AIX Level      Interim Fix (*.Z)        Fileset Name(prereq for installation) KEY
        ---------------------------------------------------------------------------------------
        7.2, 7.3       1022107a.240107.epkg.Z   openssl.base(1.0.2.2107)              key_w_fix
        7.2, 7.3       1112200a.240109.epkg.Z   openssl.base(1.1.1.2200)              key_w_fix
        7.2, 7.3       1122200a.240110.epkg.Z   openssl.base(1.1.2.2200)              key_w_fix
        7.2, 7.3       fips2108a.240108.epkg.Z  openssl.base(20.16.102.2108)          key_w_fix
        7.2, 7.3       301002sa.240122.epkg.Z   openssl.base(3.0.10.1002)             key_w_fix

        VIOS Level     Interim Fix (*.Z)        Fileset Name(prereq for installation) KEY
        ---------------------------------------------------------------------------------------
        3.1            1022107a.240107.epkg.Z   openssl.base(1.0.2.2107)              key_w_fix 
        3.1            1112200a.240109.epkg.Z   openssl.base(1.1.1.2200)              key_w_fix
        3.1            1122200a.240110.epkg.Z   openssl.base(1.1.2.2200)              key_w_fix
        3.1            fips2108a.240108.epkg.Z  openssl.base(20.16.102.2108)          key_w_fix
        3.1, 4.1       301002sa.240122.epkg.Z   openssl.base(3.0.10.1002)             key_w_fix


        To extract the fixes from the tar file:

        tar xvf openssl_fix40.tar
        cd openssl_fix40

        Verify you have retrieved the fixes intact:

        The checksums below were generated using the
        "openssl dgst -sha256 [file]" command as the following:

        openssl dgst -sha256                                              filename                 KEY
        -----------------------------------------------------------------------------------------------------
        1407212be88dbbb2d548931fd7e3b1f42ce29c51b664b38942ef61fdbbe57b4c  1022107a.240107.epkg.Z   key_w_csum
        3da47da79bd6c1fa2da6c33eedf7fd88832089aec358ad58e3d57a5ea0aede28  1112200a.240109.epkg.Z   key_w_csum
        9ae7f942c2bcfa69e840aeb98b7c16bdb979e079243b36f1baa92e37ceb0168e  1122200a.240110.epkg.Z   key_w_csum
        c818697d5319784586e90489dc45b5e751bae8fbc780a6316237d8c476227c07  301002sa.240122.epkg.Z   key_w_csum
        cc6a6215e3637be6898d538394c5ee6655f22f942e6ba7a04c2e229fe689b434  fips2108a.240108.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 AIX Support at
        https://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/openssl_advisory40.asc.sig

    B. FIX AND INTERIM FIX INSTALLATION

        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":

    https://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:

ftp://ftp.software.ibm.com/systems/power/AIX/systems_p_os_aix_security_pubkey.txt
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/openssl_advisory40.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:

Review this information as needed, no action required.

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

RELATED INFORMATION:

Security Bulletin: AIX is vulnerable to a denial of service
    (CVE-2023-5678, CVE-2023-6129, CVE-2023-6237) and an attacker may
    obtain sensitive information (CVE-2023-5363) due to OpenSSL
    https://www.ibm.com/support/pages/node/7111837

ACKNOWLEDGEMENTS:

None.

CHANGE HISTORY:

First Issued: Thu Jan 25 14:11:09 CST 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.