Cyber Resilience

CVE-2023-3909

Gitlab 12.3.0 – 16.3.6

Published
06 November 2023
Modified
05 May 2025
CVSS Score v3.1 4.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
EPSS Score 0.0060 45th percentile
Risk Priority 38 floored blend · peak EPSS

Summary

CVE-2023-3909 is a medium-severity Inefficient Regular Expression Complexity (CWE-1333) vulnerability in Gitlab Gitlab. Its CVSS base score is 4.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 45th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

An issue has been discovered in GitLab CE/EE affecting all versions starting from 12.3 before 16.3.6, all versions starting from 16.4 before 16.4.2, all versions starting from 16.5 before 16.5.1. A Regular Expression Denial of Service was possible by adding…

more

a large string in timeout input in gitlab-ci.yml file.

CWE(s)
CWE-1333

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
attack.mitre.org →
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-6688Same product: Gitlab Gitlab
CVE-2023-3994Same product: Gitlab Gitlab
CVE-2024-2651Same product: Gitlab Gitlab
CVE-2024-2829Same product: Gitlab Gitlab
CVE-2023-6682Same product: Gitlab Gitlab
CVE-2023-3424Same product: Gitlab Gitlab
CVE-2023-2198Same product: Gitlab Gitlab
CVE-2024-4025Same product: Gitlab Gitlab
CVE-2024-1495Same product: Gitlab Gitlab
CVE-2023-3364Same product: Gitlab Gitlab

Affected Assets

gitlab
gitlab
16.5.0 · 12.3.0 — 16.3.6 · 12.3.0 — 16.3.6 · 16.4.0 — 16.4.2

Mitigating Controls

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent inefficient regex via reviews, static analysis, and safe libraries.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover ReDoS issues in existing code but do not stop their introduction.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect and reject regex patterns with exponential worst-case complexity.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates review of algorithmic efficiency, directly addressing ReDoS-prone regex.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify input-validation rules that limit regex complexity.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture principles encourage avoidance of computationally expensive constructs such as catastrophic backtracking.

A.8.28 Secure coding partial match
prevents

Secure coding standards explicitly prohibit or limit the use of inefficient regular expressions.

References