VU#240785: Atlassian Bitbucket on Windows is vulnerable to privilege escalation due to weak ACLs

Vulnerability Note: VU#240785: Atlassian Bitbucket on Windows is vulnerable to privilege escalation due to weak ACLs

Published:

Description: 

Overview

Atlassian Bitbucket on Windows fails to properly set ACLs, which can allow an unprivileged Windows user to run arbitrary code with SYSTEM privileges.

Description

The Atlassian Bitbucket Windows installer fails to set a secure access-control list (ACL) on the default installation directory, such as C:AtlassianBitbucket. By default, unprivileged users can create files in this directory structure, which creates a privilege-escalation vulnerability.

Impact

By placing a specially-crafted DLL file in the Bitbucket installation directory, an unprivileged user may be able to execute arbitrary code with SYSTEM privileges on a Windows system with the vulnerable Bitbucket software installed. See DLL Search Order Hijacking for more details.

Solution

Apply an update

This issue has been addressed in the Bitbucket Windows installer for versions 7.10.1, 7.6.4, and 6.10.9. Please see https://jira.atlassian.com/browse/BSERV-12753 for more details.

Acknowledgements

This vulnerability was reported by Will Dormann of the CERT/CC.

This document was written by Will Dormann.

Source: CERT.ORG