IBM Support

Security Bulletin: AIX is vulnerable to arbitrary code execution (CVE-2024-4741) and denial of service (CVE-2024-5535, CVE-2024-4603) due to OpenSSL

Security Bulletin


Summary

Vulnerabilities in OpenSSL could allow a remote attacker to execute arbitrary code (CVE-2024-4741) or cause a denial of service (CVE-2024-5535, CVE-2024-4603). OpenSSL is used by AIX as part of AIX's secure network communications.

Vulnerability Details

CVEID:   CVE-2024-4741
DESCRIPTION:   OpenSSL could allow a remote attacker to execute arbitrary code on the system, caused by a use-after-free flaw in the SSL_free_buffers API function . By sending a specially crafted request, an attacker could exploit this vulnerability to execute arbitrary code or cause a denial of service condition.
CVSS Base score: 8.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/292512 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)

CVEID:   CVE-2024-5535
DESCRIPTION:   OpenSSL is vulnerable to a denial of service, caused by a buffer over-read flaw in the SSL_select_next_proto API function when calling with an empty supported client protocols buffer. By sending a specially crafted request, a remote attacker could exploit this vulnerability to cause a crash or memory contents to be sent to the peer.
CVSS Base score: 3.7
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/296011 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L)

CVEID:   CVE-2024-4603
DESCRIPTION:   OpenSSL is vulnerable to a denial of service, caused by improper input validation by the EVP_PKEY_param_check() or EVP_PKEY_public_check() function. By parsing a specially crafted DSA public key or DSA parameters, a remote attacker could exploit this vulnerability to cause long delays, and results in a denial of service condition.
CVSS Base score: 3.7
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/290839 for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L)

Affected Products and Versions

Affected Product(s)Version(s)
AIX7.2
AIX7.3
VIOS3.1
VIOS4.1

 

The following fileset levels are vulnerable:

 

FilesetLower LevelUpper Level
openssl.base1.1.1.01.1.1.2400
openssl.base1.1.2.01.1.2.2400
openssl.base3.0.0.03.0.13.1000

 

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. CVE-2024-4603 only applies 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/Fixes

A. FIXES

 

IBM strongly recommends addressing the vulnerability now.

 

The fixes can be downloaded via https from:

https://aix.software.ibm.com/aix/efixes/security/openssl_fix42.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.

 

You must be on the 'prereq for installation' level before applying the interim fix. This may require installing a new level(prereq version) first. The latest level of OpenSSL fileset is available from the web download site:
      https://www.ibm.com/resources/mrs/assets?source=aixbp&S_PKG=openssl

 

AIX LevelInterim FixFileset Name(prereq for installation
7.2, 7.31112400a.240722.epkg.Zopenssl.base(1.1.1.2400)
7.2, 7.31122400a.240722.epkg.Zopenssl.base(1.1.2.2400)
7.2, 7.33013sa.240722.epkg.Zopenssl.base(3.0.13.1000)

 

VIOS LevelInterim FixFileset Name(prereq for installation
3.11112400a.240722.epkg.Zopenssl.base(1.1.1.2400)
3.11122400a.240722.epkg.Zopenssl.base(1.1.2.2400)
3.1, 4.13013sa.240722.epkg.Zopenssl.base(3.0.13.1000)

 

To extract the fixes from the tar file:

tar xvf openssl_fix42.tar

cd openssl_fix42

 

Verify you have retrieved the fixes intact:

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

 

openssl dgst -sha256filename
42dbc323f64a2700e38fa4a47b71193968cea49e465577b4cda99fde219ed9831112400a.240722.epkg.Z
183eca818a3324cbaaa03b5360cc08ea86f934f08dedae553072dda2739d908a1122400a.240722.epkg.Z
556c3e6a2bb4dd94631933247199024202495c98500c6b65d74bb21e2d8b0c643013sa.240722.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 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_advisory42.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

Get Notified about Future Security Bulletins

References

Off

Acknowledgement

Change History

30 Jul 2024: 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

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SWG10","label":"AIX"},"Component":"","Platform":[{"code":"PF002","label":"AIX"}],"Version":"7.2,7.3","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSPHKW","label":"PowerVM Virtual I\/O Server"},"Component":"","Platform":[{"code":"PF002","label":"AIX"}],"Version":"3.1,4.1","Edition":"","Line of Business":{"code":"LOB57","label":"Power"}}]

Document Information

Modified date:
30 July 2024

UID

ibm17162032