Apache Log4j & CMOD ODWEK ICN

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This article discusses IBM Content Manager OnDemand (CMOD), the OnDemand Web Enablement Kit (ODWEK), IBM Content Navigator (ICN) and the Apache Log4j library, for which a Remote Code Execution (RCE) vulnerability is actively being exploited, which can give attackers elevated access, or effective control of the affected servers.

This issue has been assigned the following designation: CVE-2021-44228 and scores a 10 out of 10 on the Common Vulnerability Scoring System (CVSS)

There are now official TechNotes from IBM on the CMOD / Log4j issue:

Is IBM Content Manager OnDemand (CMOD) Version 10.5 impacted by the log4j security vulnerabilities related to CVE-2021-44228?

Is IBM Content Manager OnDemand (CMOD) Version 10.1 impacted by the log4j security vulnerabilities related to CVE-2021-44228?

If your CMOD / ODWEK / ICN solution includes WebSphere, please review the following TechNote: Multiple vulnerabilities in Apache log4j affect the IBM WebSphere Application Server

UPDATE: CMOD 10.5 FixPack 4 updates Log4j in all components. See Content Manager OnDemand FixPacks and Security Bulletins for links to IBM Fix Central


Here are some announcements from trusted sources of information on software vulnerabilities:

IBM's X-Force assessment of log4j bug

Announcement of the issue on the developer website

National Institute of Standards and Technology

Discussion of log4j v1.x susceptibility to this exploit on GitHub

Affected Versions of Log4j

Versions from v2.0 beta9 through 2.14.x are vulnerable to this exploit.

Your systems should be patched to log4j 2.16 or higher - a second vulnerability was discovered, and the latest versions disables the features by default.

Versions Shipped with CMOD

NOTE: CMOD Fixpacks with the Log4j patch have been released: CMOD Fixpacks for Log4j

CMOD Version Apache Log4j version(s) Vulnerable version?  Comment
CMOD & ODWEK v9.0 N/A N/A Log4j isn't used in CMOD v9.
CMOD & ODWEK v9.5 N/A N/A Log4j isn't used in CMOD v9.
CMOD & ODWEK v10.1 v2.6.x YES Log4j is only included with CMOD v10.1 FP6 and higher.
CMOD & ODWEK v10.5 v2.13.x YES Log4j is included in the base level and all Fixpacks of CMOD v10.5.
ICN v2.0.3 TBD TBD
ICN v3 v1.2.x NO ICN v3 is not vulnerable in the default configuration, but sites that have enabled the JMSAppender feature could be exploited.


The largest impact is to systems that have publicly-facing IBM Content Navigator (ICN) installations where the ODWEK Java API is also publicly accessible, or line-of-business (LoB) apps (like client/customer portals) that rely on Log4j to provide logging. In most (reasonable) system architectures, ODWEK itself is not exposed to the public internet, and instead, is used as an intermediate API between LoB applications that are internet-accessible and Content Manager OnDemand. In the overwhelming majority of system designs, there are firewalls and other access controls on both the external and internal sides of a web server. However, if an attacker was able to obtain an elevated level of access to a web server, they may be able to use that elevated access to attempt to exploit ODWEK.

Which CMOD components use Apache log4j?
The three components that use the log4j library are the ODWEK Java API, the REST API (new in CMOD v10.5) and the Full Text Search engine. The CMOD server itself doesn't use log4j, so none of the standard operations a CMOD server performs are vulnerable to this exploit, this includes, loading data with arsload, indexing documents with ACIF or the PDF Indexer, migrating data between cache & secondary storage, etc.
How does ODWEK Java API / REST API / FTS use the log4j library?
They are referenced through a classloader.
Is a standalone CMOD server (without IBM HTTP / Websphere / ODWEK / REST API / FTS configured) vulnerable?
No, CMOD itself does not call or use log4j.
Where do I need to install the new version of the Apache log4j library?
Anywhere that you have installed CMOD - this includes: all CMOD servers, WebSphere/Tomcat/HTTP servers with CMOD, ODWEK, or the REST API components, and development servers for line-of-business applications that use ODWEK/REST APIs.

Given that ODWEK is a niche API for a proprietary product, the risk to the data in a CMOD server is low.

Here are a list of scenarios, and the likely level of risk to this vulnerability: (Last updated Dec 13th, 10am)

  • An organization with CMOD on their internal network using Windows 'Thick' Clients: Very Low
  • CMOD and IBM Content Navigator or Line-of-Business apps that reply on ODWEK: Low
  • Line-of-Business apps using CMOD that are exposed to the public internet with proper firewalls & access controls: Low
  • Line-of-Business apps using CMOD that are exposed to the public internet with unrestricted access to the CMOD server: Low
  • CMOD and ODWEK running on the same server instance / operating system & accessible to the internet: Medium

Upgrading log4j v2.16.x

You can download the latest version of Apache log4j here: https://logging.apache.org/log4j/2.x/download.html

Please refer to IBM's Technotes for v10.1 and v10.5 for instructions on upgrading log4j on your CMOD and ODWEK installations.

Questions & Responses

If you have questions you'd like to see answered, find us on Twitter: https://Twitter.com/CMODwiki

Discuss on LinkedIn: https://www.linkedin.com/posts/justinderrick_apache-log4j-cmod-odwek-icn-activity-6875483828106932224-ledY

Discuss on the Content Manager OnDemand User Group Forums: http://www.odusergroup.org/forums/index.php/topic,3221.0.html