Cyber Resilience

CVE-2021-21383

HighPublic PoC

Published: 18 March 2021

Published
18 March 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.6 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:H/A:N
EPSS Score 0.0026 50.0th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-21383 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Requarks Wiki.Js. Its CVSS base score is 7.6 (High).

Operationally, ranked in the top 50.0% 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

Wiki.js an open-source wiki app built on Node.js. Wiki.js before version 2.5.191 is vulnerable to stored cross-site scripting through mustache expressions in code blocks. This vulnerability exists due to mustache expressions being parsed by Vue during content injection even though…

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it is contained within a `<pre>` element. By creating a crafted wiki page, a malicious Wiki.js user may stage a stored cross-site scripting attack. This allows the attacker to execute malicious JavaScript when the page is viewed by other users. For an example see referenced GitHub Security Advisory. Commit 5ffa189383dd716f12b56b8cae2ba0d075996cf1 fixes this vulnerability by adding the v-pre directive to all `<pre>` tags during the render.

CWE(s)

Related Threats

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

Affected Assets

requarks
wiki.js
≤ 2.5.191

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