Cyber Resilience

CVE-2021-33829

Medium

Published: 09 June 2021

Published
09 June 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.6553 98.5th percentile
Risk Priority 52 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-33829 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Fedoraproject Fedora. Its CVSS base score is 6.1 (Medium).

Operationally, ranked in the top 1.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

A cross-site scripting (XSS) vulnerability in the HTML Data Processor in CKEditor 4 4.14.0 through 4.16.x before 4.16.1 allows remote attackers to inject executable JavaScript code through a crafted comment because --!> is mishandled.

CWE(s)

Related Threats

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

Affected Assets

ckeditor
ckeditor
4.14.0 — 4.16.1
fedoraproject
fedora
33, 34, 35
drupal
drupal
8.9.0 — 8.9.16 · 9.0.0 — 9.0.14 · 9.1.0 — 9.1.9
debian
debian linux
9.0

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.

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