Cyber Resilience

CVE-2021-31330

MediumPublic PoC

Published: 11 May 2022

Published
11 May 2022
Modified
21 November 2024
KEV Added
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Patch
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CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0048 65.6th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-31330 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Reviewboard Review Board. Its CVSS base score is 5.4 (Medium).

Operationally, ranked in the top 34.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

A Cross-Site Scripting (XSS) vulnerability exists within Review Board versions 3.0.20 and 4.0 RC1 and earlier. An authenticated attacker may inject malicious Javascript code when using Markdown editing within the application which remains persistent.

CWE(s)
CWE-79

Related Threats

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

Affected Assets

reviewboard
review board
3.0.20, 4.0

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.

CA-8 Penetration Testing
addresses: CWE-79

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

SI-10 Information Input Validation
addresses: CWE-79

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

SI-15 Information Output Filtering
addresses: CWE-79

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

References