Vulnerability Details : CVE-2021-21254
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.
Vulnerability category: Denial of service
Products affected by CVE-2021-21254
- cpe:2.3:a:ckeditor:ckeditor5:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-21254
0.10%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 40 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-21254
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
4.0
|
MEDIUM | AV:N/AC:L/Au:S/C:N/I:N/A:P |
8.0
|
2.9
|
NIST | |
6.5
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
2.8
|
3.6
|
NIST | |
6.5
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
2.8
|
3.6
|
GitHub, Inc. |
CWE ids for CVE-2021-21254
-
The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.Assigned by: security-advisories@github.com (Primary)
References for CVE-2021-21254
-
https://github.com/ckeditor/ckeditor5/releases/tag/v25.0.0
Release v25.0.0 · ckeditor/ckeditor5 · GitHubRelease Notes;Third Party Advisory
-
https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-hgmg-hhc8-g5wr
Regular expression Denial of Service in Markdown plugin · Advisory · ckeditor/ckeditor5 · GitHubThird Party Advisory
-
https://www.npmjs.com/package/@ckeditor/ckeditor5-markdown-gfm
@ckeditor/ckeditor5-markdown-gfm - npmRelease Notes;Third Party Advisory
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