CVE-2021-21254: Uncontrolled Resource Consumption

January 29, 2021 (updated February 2, 2021)

CKEditor 5 is an open source rich text editor framework with a modular architecture. The CKEditor 5 Markdown plugin (@ckeditor/ckeditor5-markdown-gfm) before version 25.0.0 has a regex denial of service (ReDoS) vulnerability. The vulnerability allowed to abuse link recognition regular expression, which could cause a significant performance drop resulting in browser tab freeze. It affects all users using CKEditor 5 Markdown plugin at version <= 24.0.0. The problem has been recognized and patched. The fix will be available in version 25.0.0.

References

github.com/advisories/GHSA-hgmg-hhc8-g5wr
github.com/ckeditor/ckeditor5/releases/tag/v25.0.0
github.com/ckeditor/ckeditor5/security/advisories/GHSA-hgmg-hhc8-g5wr
nvd.nist.gov/vuln/detail/CVE-2021-21254
www.npmjs.com/package/@ckeditor/ckeditor5-markdown-gfm

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