GitLab Pre-Auth Remote Command Execution (CVE-2021-22205)¶
GitLab is a web-based DevOps lifecycle tool that provides a Git repository manager providing wiki, issue-tracking and continuous integration and deployment pipeline features.
An issue has been discovered in GitLab CE/EE affecting the versions starting from 11.9. GitLab was not properly validating image files that is passed to a file parser which resulted in an unauthenticated remote command execution.
References:
- https://hackerone.com/reports/1154542
- https://devcraft.io/2021/05/04/exiftool-arbitrary-code-execution-cve-2021-22204.html
- https://security.humanativaspa.it/gitlab-ce-cve-2021-22205-in-the-wild/
- https://github.com/projectdiscovery/nuclei-templates/blob/master/cves/2021/CVE-2021-22205.yaml
Vulnerable environment¶
Execute following command to start a GitLab Community Server 13.10.1:
docker compose up -d
After the server is started, browse the http://your-ip:8080 to see the website.
Exploit¶
The api endpoint /uploads/user is an unauthenticated interface. Attack the server through the poc.py:
python poc.py http://your-ip:8080 "touch /tmp/success"
touch /tmp/success has been executed successfully:
