Summary
A user with privileges to edit User macros may execute arbitrary Java code or run arbitrary system commands with the same privileges as the account running Confluence.
Product
Atlassian Confluence
Tested Version
Atlassian Confluence 7.3.3
Details
Server-Side Template Injection (Velocity)
Even though Confluence does a good job installing the Velocity SecureUberspector to sandbox the User macro templates, it stills exposes a number of objects through the Templating API that can be used to circumvent the sandbox and achieve remote code execution.
Deep inspection of the exposed objects’ object graph allows an attacker to get access to objects that allow them to instantiate arbitrary Java objects.
Impact
This issue may lead to Remote Code Execution.
CVE
CVE-2020-4027
Coordinated Disclosure Timeline
This report was subject to the GHSL coordinated disclosure policy.
- 03/23/2020: Sent report to security@atlassian.com
- 03/23/2020: Issue is acknowledged
- 06/05/2020: Fix is released as part of 7.5.1
- 06/06/2020: Additional RCE vectors are reported to Atlassian
- 06/24/2020: Fix is released
Credit
This issue was discovered and reported by GHSL team member @pwntester (Alvaro Munoz).
Contact
You can contact the GHSL team at securitylab@github.com, please include the GHSL-2020-045 in any communication regarding this issue.