CVE-2021-21254
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of service disruption.
- Exploit odds
- 1.8% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.8% in the next 30 days (EPSS).
- Severity: 6.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.8% · EPSS, next 30 days
- Weakness
- CWE-400 · Uncontrolled resource consumption
- Record status
- Modified
Affected
- Ckeditor ckeditor5 < 25.0.0
Attack profile CVSS 3.1 · 6.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-21254.md and follow it. Check whether this project is affected by CVE-2021-21254. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/ckeditor/ckeditor5/releases/tag/v25.0.0
- https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-hgmg-hhc8-g5wr
- https://github.com/ckeditor/ckeditor5/releases/tag/v25.0.0
- https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-hgmg-hhc8-g5wr
References
- https://github.com/ckeditor/ckeditor5/releases/tag/v25.0.0
- https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-hgmg-hhc8-g5wr
- https://www.npmjs.com/package/%40ckeditor/ckeditor5-markdown-gfm
- https://github.com/ckeditor/ckeditor5/releases/tag/v25.0.0
- https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-hgmg-hhc8-g5wr
- https://www.npmjs.com/package/%40ckeditor/ckeditor5-markdown-gfm