Apache Tomcat AJP RCE Vulnerability (Ghostcat) disable AJP service

[grantmcinnes]

Our 3rd party ASV is detecting an incident against our self hosted Bitbucket Server instance: 

Apache Tomcat AJP RCE Vulnerability (Ghostcat)

According to an article I found, the AJP connector service can be disabled by commenting out or removing the appropriate line from the $CATALINA_HOME/conf/server.xml file and restarting Tomcat.

Based on my understanding, Tomcat is embedded as part of Bitbucket Server and not a seperate install so how can this service be disabled?

[Daniel Eads · Accepted solution]

Hi @grantmcinnes ,

I see you've listed that you're on Bitbucket Server 7.6 in your question information. Given that, can you double-check your ASV for a specific CVE it is checking against and what its detection criteria is?

CVE-2020-1938 (Ghostcat) was mitigated in Tomcat 9.0.31, which we incorporated into Bitbucket Server starting in version 7.1.0. Bitbucket Server versions in the 7.6 line are not susceptible to CVE-2020-1938.

If by chance you are on an older version, you can look in bitbucket.properties for this string:

connector-protocol=AJP/1.3

Bitbucket Server's containerized setup is a bit different than most applications running in Tomcat - for example in Jira, you would set an AJP connector up in the server.xml file. In Bitbucket Server, configuration items like this are in the bitbucket.properties file. 

It is very uncommon to have AJP enabled with Bitbucket Server, although it is possible. I would go through those two steps to see if this is something you need to modify:

1. Bitbucket Server 7.6 has a mitigated Tomcat version - no need for concern on this version or newer
2. If you're on Bitbucket Server older than version 7.1.0, check the bitbucket.properties file for an enabled AJP connector

Let me know what you find and we'll get you sorted if there's something to change!

Cheers,
Daniel | Atlassian Support

[grantmcinnes]

@Daniel Eads Thanks for the reply.