Security Bulletin: IBM Kenexa LCMS Premier On Premise - Log4j - CVE-2021-4104 (Publicly disclosed vulnerability)

Summary

We have identified that the IBM Kenexa LCMS Premier is affected by one or more security vulnerabilities. These have been tested in LCMS Premier 13.x & 14.0 versions.

Vulnerability Details

CVEID:CVE-2021-4104
**DESCRIPTION:**Apache Log4j could allow a remote attacker to execute arbitrary code on the system, caused by the deserialization of untrusted data when the attacker has write access to the Log4j configuration. If the deployed application is configured to use JMSAppender, an attacker could exploit this vulnerability to execute arbitrary code on the system.
CVSS Base score: 8.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/215048 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)

Affected Products and Versions

Remediation/Fixes

LCMS uses Log4j 1.x version and fix for this issue has been tested on IBM LCMS 13.x & 14.0 versions

Steps to Download from Fix Central

• Log in to Fix Central (<https://www-945.ibm.com/support/fixcentral/&gt;)
• Select "IBM Kenexa LCMS Premier” from the Product Selector dropdown
• Select “14.0” from the Installed version dropdown
• Select “Windows” from the Platform dropdown
• Click “Continue”
• Select "Browse for Fixes” and click “Continue”

Download log4jLcmsfix.zip and Extract the following 2 files:

• libreplace.exe
• log4j-core-2.15.0.jar

Steps to Follow:

Steps for deploying log4j fix:

1. Copy libreplace.exe and log4j-core-2.15.0.jar into a new directory, e.g. c:\log4jfix

2. Start a command-prompt as administrator

3. Change to new directory, e.g. cd /d c:\log4jfix

4. Stop all LCMS services

5. Execute command-line:

libreplace.exe “d:\lcms” log4j*.jar log4j-core-2.15.0.jar . CONFIRM

(“d:\lcms” represents your LCMS directory)

6. Notice log messages that look like “log4j(etc).jar is now identical to log4j-core-2.15.0.jar”; this confirms that changes have been made properly

7. Start LCMS services

OPTIONAL - to rollback changes(if needed):

1. Stop all LCMS services

2. Find the .log file in e.g. c:\log4jfix

3. Find every line that starts with “UNDO:”

4. Execute the OS command from command-line, which follows “UNDO:”

5. Start LCMS services

Workarounds and Mitigations

None