Bamboo Security Advisory 2018-03-28

Bamboo  - Argument injection through Mercurial repository URI handling on Windows - CVE-2018-5224

Note: As of  September 2014 we are no longer issuing binary bug patches, instead we create new maintenance releases for the major versions we are backporting.

Summary of Vulnerability

This advisory discloses a critical severity security vulnerability which was introduced in version 2.7.0 of Bamboo. Versions of Bamboo starting with 2.7.0 before 6.3.3 (the fixed version for 6.3.x) and from version 6.4.0 before 6.4.1 (the fixed version for 6.4.x) running on the Windows operating system are affected by this vulnerability. 

Argument injection through Mercurial repository URI handling on Windows (CVE-2018-5224)

Severity

Atlassian rates the severity level of this vulnerability as critical, according to the scale published in our Atlassian severity levels. The scale allows us to rank the severity as critical, high, moderate or low.

This is our assessment and you should evaluate its applicability to your own IT environment.

Description

Bamboo did not correctly check if a configured Mercurial repository URI contained values that the Windows operating system may consider argument parameters.  An attacker who has permission to do one or more of the following:

• create a repository in Bamboo
• edit an existing plan in Bamboo that has a non-linked Mercurial repository
• create a plan in Bamboo either globally or in a project using Bamboo Specs

can execute code of their choice on systems that run a vulnerable version of Bamboo on the Windows operating system.

All versions of Bamboo starting with 2.7.0 before 6.3.3 (the fixed version for 6.3.x) and from version 6.4.0 before 6.4.1 (the fixed version for 6.4.x) running on the Windows operating system are affected by this vulnerability.

This issue can be tracked here:  https://jira.atlassian.com/browse/BAM-19743.

Acknowledgements

Atlassian would like to credit Zhang Tianqi @ Tophant for reporting this issue to us.

Mitigation

Disable the "Atlassian Bamboo Mercurial Repository Plugin" via the Addons menu in the Administration section.

Note: "Atlassian Bamboo Bitbucket Repository Plugin" depends on "Atlassian Bamboo Mercurial Repository Plugin" therefore it will be disabled as well, as an effect any Bitbucket Cloud repository in Bamboo will stop working. Reenabling "Atlassian Bamboo Bitbucket Repository Plugin" will reenable "Atlassian Bamboo Mercurial Repository Plugin" making your system vulnerable again. 

Fix

We have taken the following steps to address this issue:

1. Released Bamboo version 6.4.1 that contains a fix for this issue and can be downloaded from https://www.atlassian.com/software/bamboo/download.
2. Released Bamboo version 6.3.3 that contains a fix for this issue and can be downloaded from https://www.atlassian.com/software/bamboo/download-archives.

What You Need to Do

Atlassian recommends that you upgrade to the latest version. For a full description of the latest version of Bamboo, see the release notes. You can download the latest version of Bamboo from the download centre.

Upgrade Bamboo to version 6.4.1 or higher.

If you are running Bamboo 6.3.x and cannot upgrade to 6.4.1 then upgrade to version 6.3.3.

Support

If you did not receive an email for this advisory and you wish to receive such emails in the future go to https://my.atlassian.com/email and subscribe to Alerts emails.

If you have questions or concerns regarding this advisory, please raise a support request at https://support.atlassian.com/.

References