AIX is vulnerable to a denial of service due to the AIX SMB client

IBM SECURITY ADVISORY

First Issued: Wed Dec 20 12:50:52 CST 2023

The most recent version of this document is available here:

https://aix.software.ibm.com/aix/efixes/security/smbcd_advisory3.asc

Security Bulletin: AIX is vulnerable to a denial of service due to the AIX SMB
client (CVE-2023-45165)

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

SUMMARY:

A vulnerability in the AIX SMB client daemon could allow a non-privileged
local user to cause a denial of service (CVE-2023-45165). AIX uses the
SMB client daemon to access files on SMB servers.

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

VULNERABILITY DETAILS:

CVEID: CVE-2023-45165
    https://vulners.com/cve/CVE-2023-45165
DESCRIPTION: IBM AIX could allow a non-privileged local user to exploit a
    vulnerability in the AIX SMB client to cause a denial of service.
CVSS Base Score: 6.2
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/267963
    for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)


AFFECTED PRODUCTS AND VERSIONS:

    AIX 7.2, 7.3

    The following fileset levels are vulnerable:
    
    key_fileset = osrcaix

    Fileset                 Lower Level   Upper Level    KEY
    -------------------------------------------------------------
    smbc.rte                7.2.0.0       7.2.302.10     key_w_fs

    To determine if your system is vulnerable, execute the
    following commands:

    lslpp -L | grep -i smbc.rte

REMEDIATION:

    FIXES

        IBM strongly recommends addressing the vulnerability now.

        The latest SMB client fileset may be downloaded from:
        https://www.ibm.com/resources/mrs/assets?source=aixbp

        To extract the fixes from the tar file:

        For AIX 7.2 and 7.3 TL0:
        gunzip smbc_302_fileset_72.tar.gz | tar xvf

        For AIX 7.3 TL1:
        gunzip smbc_302_fileset_73.tar.gz | tar xvf

        IMPORTANT: 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 the fix installation:

        installp -apYd . smbc

        To install the fix package:

        installp -aXYd . smbc


WORKAROUNDS AND MITIGATIONS:

    None.

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CONTACT US:

Note: Keywords labeled as KEY in this document are used for parsing
purposes.

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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 security bulletin:

    Published advisory OpenSSL signature file location:

    https://aix.software.ibm.com/aix/efixes/security/smbcd_advisory3.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:
    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 due to the 
    AIX SMB client (CVE-2023-45165)
    https://www.ibm.com/support/pages/node/7100970

ACKNOWLEDGEMENTS:

None.

CHANGE HISTORY:

First Issued: Wed Dec 20 12:50:52 CST 2023

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

*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.