Vulnerability Report

CVE-2021-21254

Title: CKEditor 5 Markdown Plugin Regex Denial of Service (ReDoS)

DoS

Proof Of Concept

No public PoC currently indexed for CVE-2021-21254.

CWE Category CWE-400
Published Date Jan 29, 2021
Modified Date Nov 21, 2024
Exploit Status Not Found
Score 6.5 CVSS v3.1
Exploit Probability (EPSS)
1.79%

Vulnerability Summary

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.

Impacted Vendors

C
ckeditor 1

Reference Links

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
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
6.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS v3.1
Source Entity [email protected]
Severity MEDIUM
6.5
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS v2.0
Source Entity [email protected]
Severity MEDIUM
4.0
Access Vector
N/A
Authentication
N/A
RAW VECTOR AV:N/AC:L/Au:S/C:N/I:N/A:P

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2021-21254 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data or affected products updated.

PUBLISHED

Vulnerability first announced in NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected Stack

No specific products linked.