Cyber Resilience

CVE-2021-39885

HighPublic PoC

Published: 04 October 2021

Published
04 October 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 8.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
EPSS Score 0.0022 44.3th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-39885 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Gitlab Gitlab. Its CVSS base score is 8.7 (High).

Operationally, ranked at the 44.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

A Stored XSS in merge request creation page in all versions of Gitlab EE starting from 13.7 before 14.1.7, all versions starting from 14.2 before 14.2.5, and all versions starting from 14.3 before 14.3.1 allows an attacker to execute arbitrary…

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JavaScript code on the victim's behalf via malicious approval rule names

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

gitlab
gitlab
14.3.0 · 13.7.0 — 14.1.7 · 14.2.0 — 14.2.5

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References