NetSight
IP …
medium6.5

CVE-2021-21391

Regular expression Denial of Service in multiple packages

Impact

### Impact A regular expression denial of service (ReDoS) vulnerability has been discovered in multiple CKEditor 5 packages. The vulnerability allowed to abuse particular regular expressions, which could cause a significant performance drop resulting in a browser tab freeze. It affects all users using the CKEditor 5 packages listed above at version <= 26.0.0. ### Patches The problem has been recognized and patched. The fix will be available in version 27.0.0. ### For more information Email us at security@cksource.com if you have any questions or comments about this advisory. ### Acknowledgements The CKEditor 5 team would like to thank Yeting Li for recognizing and reporting these vulnerabilities.

Affected packages

EcosystemPackageAffectedFixed in
npm@ckeditor/ckeditor5-engine<= 26.0.027.0.0
npm@ckeditor/ckeditor5-font<= 26.0.027.0.0
npm@ckeditor/ckeditor5-image<= 26.0.027.0.0
npm@ckeditor/ckeditor5-list<= 26.0.027.0.0
npm@ckeditor/ckeditor5-markdown-gfm<= 26.0.027.0.0
npm@ckeditor/ckeditor5-media-embed<= 26.0.027.0.0
npm@ckeditor/ckeditor5-paste-from-office<= 26.0.027.0.0
npm@ckeditor/ckeditor5-widget<= 26.0.027.0.0

Affected products

VendorProductAffected versions
CkeditorCkeditor5-Engine
before 27.0.0
CkeditorCkeditor5-Font
before 27.0.0
CkeditorCkeditor5-Image
before 27.0.0
CkeditorCkeditor5-List
before 27.0.0
CkeditorCkeditor5-Markdown-Gfm
before 27.0.0
CkeditorCkeditor5-Media-Embed
before 27.0.0
CkeditorCkeditor5-Paste-From-Office
before 27.0.0
CkeditorCkeditor5-Widget
before 27.0.0

Weakness classification

CWE-400

References