Security Bulletin: AIX is vulnerable to a denial of service (CVE-2024-2511, CVE-2024-0727) due to OpenSSL

Summary

Vulnerabilities in OpenSSL could allow a remote attacker to cause a denial of service (CVE-2024-2511, CVE-2024-0727). OpenSSL is used by AIX as part of AIX’s secure network communications.

Vulnerability Details

CVEID:CVE-2024-2511
**DESCRIPTION:**OpenSSL is vulnerable to a denial of service, caused by improper server configuration validation. By using a specially crafted server configuration, a remote attacker could exploit this vulnerability to cause unbounded memory growth, and results in a denial of service condition.
CVSS Base score: 3.7
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/287215 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-2024-0727
**DESCRIPTION:**OpenSSL is vulnerable to a denial of service, caused by improper input validation. By persuading a victim to open a specially crafted PKCS12 file, a remote attacker could exploit this vulnerability to cause the application to crash.
CVSS Base score: 3.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/280532 for the current score.
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

The following fileset levels are vulnerable:

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

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

FIXES

IBM strongly recommends addressing the vulnerability now.

A fix is available, and it can be downloaded from:

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

To extract the fixes from the tar file:

For OpenSSL 3.0:

zcat openssl-3.0.13.1000.tar.Z | tar xvf -

For OpenSSL 1.1.1 with no weak ciphers support:

zcat openssl-1.1.2.2400.tar.Z | tar xvf -

For OpenSSL 1.1.1 with all ciphers support:

zcat openssl-1.1.1.2400.tar.Z | 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.

Note that all the previously reported security vulnerability fixes are also included in above mentioned fileset level. Please refer to the readme file (provided along with the fileset) for the complete list of vulnerabilities fixed.

To preview the fix installation:

installp -apYd . openssl

To install the fix package:

installp -aXYd . openssl

To verify the signature files:

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_advisory41.asc.sig&gt;

Workarounds and Mitigations

None