PT-2021-14470 · Unknown · Ckeditor 5

Yeting Li · Published 2021-04-06 · Updated 2021-05-10 · CVE-2021-21391

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions CKEditor 5 versions <= 26.0.0

Description A regular expression denial of service (ReDoS) vulnerability has been discovered in multiple CKEditor 5 packages, including ckeditor5-engine, ckeditor5-font, ckeditor5-image, ckeditor5-list, ckeditor5-markdown-gfm, ckeditor5-media-embed, ckeditor5-paste-from-office, and ckeditor5-widget. This issue allows the abuse of particular regular expressions, causing a significant performance drop and potentially resulting in a browser tab freeze.

Recommendations For versions <= 26.0.0, update to version 27.0.0 to resolve the issue. As a temporary workaround, consider restricting the use of the affected CKEditor 5 packages until the patch is applied.

Fix

Resource Exhaustion

Weakness Enumeration

CWE-400

Related Identifiers

CVE-2021-21391

GHSA-3RH3-WFR4-76MJ

Affected Products

Ckeditor 5

References · 24

• https://cve.org/CVERecord?id=CVE-2021-21391 · Security Note
• https://osv.dev/vulnerability/CVE-2021-21391 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-21391 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2021-21391 · Security Note
• https://osv.dev/vulnerability/GHSA-3rh3-wfr4-76mj · Vendor Advisory
• https://ubuntu.com/security/CVE-2021-21391 · Vendor Advisory
• https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-3rh3-wfr4-76mj · Note
• https://github.com/ckeditor/ckeditor5/releases/tag/v27.0.0 · Note
• https://npmjs.com/package/@ckeditor/ckeditor5-engine · Note
• https://npmjs.com/package/%40ckeditor/ckeditor5-paste-from-office · Note
• https://npmjs.com/package/%40ckeditor/ckeditor5-list · Note
• https://npmjs.com/package/%40ckeditor/ckeditor5-markdown-gfm · Note
• https://npmjs.com/package/@ckeditor/ckeditor5-widget · Note
• https://npmjs.com/package/%40ckeditor/ckeditor5-media-embed · Note
• https://npmjs.com/package/@ckeditor/ckeditor5-markdown-gfm · Note