Is Cromwell affected by log4shell ?

A simple grep through the source code reveals several hits with Log4j:

CromwellRefdiskManifestCreator/pom.xml:            <groupId>org.apache.logging.log4j</groupId>
CromwellRefdiskManifestCreator/pom.xml:            <artifactId>log4j-core</artifactId>
CromwellRefdiskManifestCreator/pom.xml:            <groupId>org.apache.logging.log4j</groupId>
CromwellRefdiskManifestCreator/pom.xml:            <artifactId>log4j-api</artifactId>
CromwellRefdiskManifestCreator/src/main/java/org/broadinstitute/manifestcreator/CromwellRefdiskManifestCreatorApp.java:import org.apache.logging.log4j.Level;
CromwellRefdiskManifestCreator/src/main/java/org/broadinstitute/manifestcreator/CromwellRefdiskManifestCreatorApp.java:import org.apache.logging.log4j.LogManager;
CromwellRefdiskManifestCreator/src/main/java/org/broadinstitute/manifestcreator/CromwellRefdiskManifestCreatorApp.java:import org.apache.logging.log4j.Logger;
CromwellRefdiskManifestCreator/src/main/java/org/broadinstitute/manifestcreator/CromwellRefdiskManifestCreatorApp.java:import org.apache.logging.log4j.core.config.Configurator;
project/Dependencies.scala:    // Replace all log4j usage with slf4j
project/Dependencies.scala:    // https://www.slf4j.org/legacy.html#log4j-over-slf4j
project/Dependencies.scala:    "org.slf4j" % "log4j-over-slf4j" % slf4jV

I wasn’t able to expose a vulnerability by using malicious code but my test is probably not extensive. It looks like this lib is used in a packaging tool of Cromwell so probably not executed during production. On the other hand, slj4j seems to be used everywere. Is that abstraction layer vulnerable ?

Could you please let us know if you believe Cromwell is affected by Log4shell ?

Thanks,

[aednichols]

We redundantly re-verified the absence of the problem class [0] by unzipping the shipping Cromwell JAR and manually checking that the path is empty.

[0] org/apache/logging/log4j/core/lookup/JndiLookup.class

[aednichols]

Cromwell itself does not use Log4j.

This can be verified by executing sbt dependencyTree and noting that all instances of “log4j” occur in org.slf4j:log4j-over-slf4j which is a Log4j compatibility bridge from a different project.

The utility tool CromwellRefdiskManifestCreator is written in Java and does use Log4j. It is not included in the Cromwell JAR. It is being updated presently.