CVE-2016-4340

HIGH

GitLab 8.2.0-8.6.7 Authenticated Privilege Escalation via Impersonate

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2016-4340. PoCs published by Kaimi.

AI-analyzed exploit summary This exploit demonstrates a privilege escalation vulnerability in GitLab where any registered user can impersonate another user, including administrators, by crafting a specific POST request with a valid authenticity token. The vulnerability affects multiple versions of GitLab from 8.2.0 to 8.7.0.

Description

The impersonate feature in Gitlab 8.7.0, 8.6.0 through 8.6.7, 8.5.0 through 8.5.11, 8.4.0 through 8.4.9, 8.3.0 through 8.3.8, and 8.2.0 through 8.2.4 allows remote authenticated users to "log in" as any other user via unspecified vectors.

Exploits (1)

exploitdb WORKING POC
by Kaimi · textwebappsruby
https://www.exploit-db.com/exploits/40236

This exploit demonstrates a privilege escalation vulnerability in GitLab where any registered user can impersonate another user, including administrators, by crafting a specific POST request with a valid authenticity token. The vulnerability affects multiple versions of GitLab from 8.2.0 to 8.7.0.

Classification
Working Poc 90%
Attack Type
Auth Bypass
Complexity
Trivial
Reliability
Reliable
Target: GitLab versions 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
Auth required
Prerequisites: Valid user account · Authenticity token from a POST request
devstral-2 · analyzed Feb 16, 2026 Full analysis →

References (4)

Core 4
Core References
Mitigation, Patch, Vendor Advisory x_refsource_confirm
https://about.gitlab.com/2016/05/02/cve-2016-4340-patches/
Exploit, Third Party Advisory, VDB Entry exploit x_refsource_exploit-db
https://www.exploit-db.com/exploits/40236/
Issue Tracking, Patch, Vendor Advisory x_refsource_confirm
https://gitlab.com/gitlab-org/gitlab-ce/issues/15548
Exploit, Third Party Advisory, VDB Entry x_refsource_misc
http://packetstormsecurity.com/files/138368/GitLab-Impersonate-Privilege-Escalation.html

Scores

CVSS v3 8.8
EPSS 0.1014
EPSS Percentile 95.1%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-264
Status published
Products (45)
gitlab/gitlab 8.2.0
gitlab/gitlab 8.2.1
gitlab/gitlab 8.2.2
gitlab/gitlab 8.2.3
gitlab/gitlab 8.2.4
gitlab/gitlab 8.3.0
gitlab/gitlab 8.3.1
gitlab/gitlab 8.3.2
gitlab/gitlab 8.3.3
gitlab/gitlab 8.3.4
... and 35 more
Published Jan 23, 2017
Tracked Since Feb 18, 2026