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Security Bulletin: AIX is vulnerable to a denial of service due to libxml2 (CVE-2022-29824)

Security Bulletin


Summary

A vulnerability in libxml2 could allow a remote attacker to cause a denial of service (CVE-2022-29824). AIX uses libxml2 as part of its XML parsing functions.

Vulnerability Details

CVEID:   CVE-2022-29824
DESCRIPTION:   GNOME libxml2 is vulnerable to a denial of service, caused by an integer overflows in several buffer handling functions in buf.c (xmlBuf*) and tree.c (xmlBuffer*). By persuading a victim to open a specially-crafted XML file, a remote attacker could exploit this vulnerability to cause a denial of service condition.
CVSS Base score: 5.5
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/225645 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H)

Affected Products and Versions

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

The following fileset levels are vulnerable:

Fileset Lower Level Upper Level
bos.rte.control 7.2.4.0 7.2.4.5
bos.rte.control 7.2.5.0 7.2.5.2
bos.rte.control 7.2.5.100 7.2.5.101
bos.rte.control 7.3.0.0 7.3.0.1

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.control

Remediation/Fixes

A. APARS
         
IBM has assigned the following APARs to this problem:
AIX Level APAR SP
7.2.4 IJ42381 N/A
7.2.5 IJ42339 SP06
7.3.0 IJ42341 SP04
 
VIOS Level APAR SP
3.1.1 IJ42381 N/A
3.1.2 IJ42378 3.1.2.60
3.1.3 IJ42379 3.1.3.40

Subscribe to the APARs here:

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
IBM strongly recommends addressing the vulnerability now.
AIX and VIOS fixes are available.
The AIX and VIOS fixes can be downloaded via ftp or http from:
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
7.2.4.4 IJ42381s6a.220909.epkg.Z
7.2.4.5 IJ42381s6a.220909.epkg.Z
7.2.4.6 IJ42381s6a.220909.epkg.Z
7.2.5.2 IJ42339s2a.220909.epkg.Z
7.2.5.3 IJ42339s4a.220907.epkg.Z
7.2.5.4 IJ42339s4a.220907.epkg.Z
7.3.0.1 IJ42341s2a.220907.epkg.Z
7.3.0.2 IJ42341s2a.220907.epkg.Z

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
3.1.1.40 IJ42381s6a.220909.epkg.Z
3.1.1.50 IJ42381s6a.220909.epkg.Z
3.1.1.60 IJ42381s6a.220909.epkg.Z
3.1.2.21 IJ42378s2a.220909.epkg.Z
3.1.2.30 IJ42378s2a.220909.epkg.Z
3.1.2.40 IJ42378s2a.220909.epkg.Z
3.1.3.10 IJ42379s4a.220909.epkg.Z
3.1.3.14 IJ42379s4a.220909.epkg.Z
3.1.3.21 IJ42379s4a.220909.epkg.Z

To extract the fixes from the tar file:
tar xvf libxml2_fix3.tar
cd libxml2_fix3
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
f6d71f263ee414469dde9e6c3325fbc56031d3098ee8831f330e90c9e6b4dd9a IJ42339s2a.220909.epkg.Z
062b34620bc669451695f0de09580aef6e16f36f6430654dee5c403d23bc2fcc IJ42339s4a.220907.epkg.Z
562b5f19d4db9e4c8835fd92f2e65038c2d765f0ff5e3ef40bad2d9110403a26 IJ42341s2a.220907.epkg.Z
f5ec81e718eef7d02adfb85a70f626073f684b93d72173212ba5675fe1eff001 IJ42378s2a.220909.epkg.Z
e00696e638622f82a2264b994fff9415b55c323a271da4c4bb84626046aa031c IJ42379s4a.220909.epkg.Z
f03c422e62ea819fa2dfc56342a16da80d20df4444667c6fae97ae95c1c2f6dd IJ42381s6a.220909.epkg.Z

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:
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:
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

Get Notified about Future Security Bulletins

References

Off

Change History

12 Sep 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:
12 September 2022

UID

ibm16619729