Security Bulletin: IBM® Db2® is vulnerable to a denial of service as the server may crash when when attempting to use ACR client affinity for unfenced DRDA federation wrappers. (CVE-2023-27555)

Summary

IBM® Db2® is vulnerable to a denial of service as the server may crash when when attempting to use ACR client affinity for unfenced DRDA federation wrappers.

Vulnerability Details

CVEID:CVE-2023-27555
**DESCRIPTION:**IBM Db2 for Linux, UNIX and Windows (includes DB2 Connect Server) is vulnerable to a denial of service when attempting to use ACR client affinity for unfenced DRDA federation wrappers.
CVSS Base score: 5.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/249187 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)

Affected Products and Versions

All fix pack levels of IBM Db2 V11.5 server editions on all platforms are affected.

IBM Db2 V11.1 and 10.5 are not affected.

Remediation/Fixes

Customers running any vulnerable fixpack level of an affected Program, V11.5, can download the special build containing the interim fix for this issue from Fix Central. These special builds are available based on the most recent fixpack level for each impacted release: v11.5.7 and V11.5.8. They can be applied to any affected fixpack level of the appropriate release to remediate this vulnerability.

Special Build for V11.5.7:

AIX 64-bit
Linux 32-bit, x86-32
Linux 64-bit, x86-64
Linux 64-bit, POWER™ little endian
Linux 64-bit, System z®, System z9® or zSeries®
Windows 32-bit, x86
Windows 64-bit, x86

Special Build for V11.5.8:

AIX 64-bit
Linux 32-bit, x86-32
Linux 64-bit, x86-64
Linux 64-bit, POWER™ little endian
Linux 64-bit, System z®, System z9® or zSeries®
Windows 32-bit, x86
Windows 64-bit, x86

IBM does not disclose key Db2 functionality nor replication steps for a vulnerability to avoid providing too much information to any potential malicious attacker. IBM does not want to enable a malicious attacker with sufficient knowledge to craft an exploit of the vulnerability.

Workarounds and Mitigations

Remove the unsupported options from the db2dsdriver.cfg configuration for the federated data source. If the configuration cannot be changed because it shared with other applications then provide a separate configuration for the federated data source.