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Security Bulletin: AIX is vulnerable to a denial of service due to the AIX SMB client (CVE-2022-43381)

Security Bulletin


Summary

A vulnerability in the AIX SMB client daemon could allow a non-privileged local user to cause a denial of service (CVE-2022-43381). AIX uses the SMB client daemon to access files on SMB servers.

Vulnerability Details

CVEID:   CVE-2022-43381
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/238639 for the current score.
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

Affected Product(s) Version(s)
AIX 7.1
AIX 7.2
AIX 7.3
VIOS 3.1

The following fileset levels are vulnerable:

Fileset Lower Level Upper Level
smbc.rte 7.1.0.0 7.1.302.8
smbc.rte 7.2.0.0 7.2.302.8

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

lslpp -L | grep -i smbc.rte

Remediation/Fixes

FIXES

IBM strongly recommends addressing the vulnerability now.

The fixes can be downloaded via ftp or http from:

ftp://aix.software.ibm.com/aix/efixes/security/smbcd_fix2.tar

http://aix.software.ibm.com/aix/efixes/security/smbcd_fix2.tar

https://aix.software.ibm.com/aix/efixes/security/smbcd_fix2.tar

The latest SMB client fileset may also be downloaded from:

https://www.ibm.com/resources/mrs/assets?source=aixbp

To extract the fixes from the tar file:

For AIX 7.1:

tar xvf smbcd_fix2.tar

gunzip smbc_302_fileset_71.tar.gz | tar xvf

For AIX 7.2, 7.3, and VIOS 3.1:

tar xvf smbcd_fix2.tar

gunzip smbc_302_fileset_72.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

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
261e08badda1c179e487c2ee20b772cea526a9868a3fd9a8b5c66479a7cb95ca smbc_302_fileset_71.tar.gz
e99d99ce8336a61a888c826c43a97869f3a2df8fcacd59b141770b5ad98a86fc smbc_302_fileset_72.tar.gz

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 [fix_file].sig [fix_file]

Published advisory OpenSSL signature file location:

http://aix.software.ibm.com/aix/efixes/security/smbcd_advisory2.asc.sig

https://aix.software.ibm.com/aix/efixes/security/smbcd_advisory2.asc.sig

ftp://aix.software.ibm.com/aix/efixes/security/smbcd_advisory2.asc.sig

Workarounds and Mitigations

None

Get Notified about Future Security Bulletins

References

Off

Change History

05 Jan 2023: No change - fixed minor typo
14 Dec 2022: Initial Publication

*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. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.

Document Location

Worldwide

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Document Information

Modified date:
05 January 2023

UID

ibm16851443