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

Summary

We have identified that the IBM Kenexa LMS On Premise is affected by one or more security vulnerabilities. These have been tested in LMS 6.1.0 version.

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

LMS uses Log4j 1.x version and the fix for this issue has been tested on IBM LMS 6.1.

Steps to Download from Fix Central

• Log in to Fix Central (<https://www-945.ibm.com/support/fixcentral/&gt;)
• Select " IBM Kenexa LMS” from the Product Selector dropdown
• Select “6.1” from the Installed version dropdown
• Select “Windows” from the Platform dropdown
• Click “Continue”
• Select "Browse for Fixes” and click “Continue”

Download log4jLMSfix.zip and Extract the following 2 files:

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

Steps to Follow in version 6.1:

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 LMS\Participate services

5. Execute command-line:

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

(“d:\lmspe\lms” represents your LMS directory, not your Participate 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. (*see note below) Execute command-line:

libreplace.exe “d:\lmspe\pe101” log4j*.jar log4j-core-2.15.0.jar . CONFIRM

(“d:\lmspe\pe101” represents your Participate directory, not your LMS directory)

8. 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

9. Start LMS/Participate services

*Note: following step #7 will most likely break search function within Participate. Courses will still launch but searching for enrollments or any other listing of courses will not work. You can omit step #7 if this is loss of search function is unacceptable.

OPTIONAL - to rollback changes (if needed):

1. Stop all LMS 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 LMS services

Workarounds and Mitigations

None