CVE-2023-6680 - CVE House
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Status published High CVE-2023-6680

Improper Certificate Validation in GitLab

Vulnerability Description

An improper certificate validation issue in Smartcard authentication in GitLab EE affecting all versions from 11.6 prior to 16.4.4, 16.5 prior to 16.5.4, and 16.6 prior to 16.6.2 allows an attacker to authenticate as another user given their public key if they use Smartcard authentication. Smartcard authentication is an experimental feature and has to be manually enabled by an administrator.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Thanks Lucas Serrano from PEReN (@LSerranoPEReN) for reporting this vulnerability

References

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Affected Vendor

Affected Software

GitLab
Vulnerable Versions:
11.6, 16.5, 16.6

Timeline

Official Publish: December 15th, 2023
Last Modified: June 6th, 2026
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Weaknesses (CWE)

CWE-295

MITRE ATT&CK TTPs

T1557 Adversary-in-the-Middle
Credential Access
T1040 Network Sniffing
Collection
T1552 Unsecured Credentials
Credential Access
T1071 Application Layer Protocol
Command and Control
T1565 Data Manipulation
Impact