CVE-2019-11580: Proof-of-Concept for Critical Atlassian Crowd Remote Code Execution Vulnerability Now Available

Satnam Narang

A proof-of-concept for critical Atlassian Crowd vulnerability patched on May 22 is now available.

Background

On July 14, security researcher Corben Leo published a blog detailing the analysis of a recently patched vulnerability in Atlassian Crowd, a user management application for access control for Active Directory (AD), Lightweight Directory Access Protocol (LDAP), OpenLDAP and Microsoft Azure AD.

Analysis

On May 22, Atlassian published Crowd Security Advisory 2019-05-22 to address CVE-2019-11580. According to the advisory, Crowd and Crowd Data Center incorrectly enabled a development plugin for pdkinstall in release builds. A remote attacker could exploit this flaw to install arbitrary plugins by sending unauthenticated or authenticated requests to vulnerable Crowd or Crowd Data Center instances, which could grant them the ability to execute code.

Leo’s blog post provides analysis of the pdkinstall plugin and the PdkInstallFilter servlet, which he used to craft a proof-of-concept (PoC) that allowed him to gain pre-authenticated remote code execution in Atlassian Crowd.

Image credit: Corben Leo

Proof of concept

Leo published a malicious plugin on GitHub to be used as part of a PoC included in his blog post:

curl -k -H "Content-Type: multipart/mixed" \ --form "file_cdl=@rce.jar" http://localhost:4990/crowd/admin/uploadplugin.action

Solution

Atlassian published patched versions of Crowd and Crowd Data Center on May 22. The patched versions include 3.0.5, 3.1.6, 3.2.8, 3.3.5, and 3.4.4. The following table lists the vulnerable versions and the associated fixed versions.

Affected Versions

Fixed Version

2.1.0, 2.1.1, 2.1.2, 2.2.0, 2.2.1, 2.2.2, 2.2.3, 2.2.4, 2.2.5, 2.2.6, 2.2.7, 2.2.8, 2.2.9, 2.3.0, 2.3.1, 2.3.2, 2.3.3, 2.3.4, 2.3.5, 2.3.6, 2.3.7, 2.3.8, 2.3.9, 2.3.10, 2.4.0, 2.4.1, 2.4.2, 2.4.3, 2.4.4, 2.4.5, 2.4.6, 2.4.7, 2.4.8, 2.4.9, 2.4.10, 2.4.11, 2.5.0, 2.5.1, 2.5.2, 2.5.3, 2.5.4, 2.5.5, 2.5.6, 2.5.7, 2.6.0, 2.6.1, 2.6.2, 2.6.3, 2.6.4, 2.6.5, 2.6.6, 2.6.7, 2.7.0, 2.7.1, 2.7.2, 2.8.0, 2.8.1, 2.8.2, 2.8.3, 2.8.4, 2.8.6, 2.8.7, 2.8.8, 2.9.1, 2.9.2, 2.9.3, 2.9.4, 2.9.5, 2.9.6, 2.9.7, 2.10.1, 2.10.2, 2.10.3, 2.10.4, 2.11.0, 2.11.1, 2.11.2, 2.12.0, 2.12.1, 3.0.0, 3.0.1, 3.0.2, 3.0.3, 3.0.4

3.0.5

3.1.0, 3.1.1, 3.1.2, 3.1.3, 3.1.4, 3.1.5

3.1.6

3.2.0, 3.2.1, 3.2.2, 3.2.3, 3.2.4, 3.2.5, 3.2.6, 3.2.7

3.2.8

3.3.0, 3.3.1, 3.3.2, 3.3.3, 3.3.4

3.3.5

3.4.0, 3.4.1, 3.4.2, 3.4.3

3.4.4

If upgrading to a patched version of Atlassian Crowd is not feasible at this time, Atlassian provided mitigation steps in their Security Advisory to address the vulnerability as well as a bash script to automate the mitigation steps on Linux systems.

Identifying affected systems

A list of Tenable plugins to identify this vulnerability can be found here.

Get more information 

Join Tenable's Security Response Team on the Tenable Community.

Learn more about Tenable, the first Cyber Exposure platform for holistic management of your modern attack surface. Get a free 60-day trial of Tenable.io Vulnerability Management.

Read more >

Published on Jul 15, 2019

We have big plans for continued global growth, and we’re looking for people who are creative, flexible and dedicated to helping us build something great – something that matters.