CVE-2021-21254 Regular expression Denial of Service in Markdown plugin

2021-01-2921:55:14

CWE-400

GitHub_M

www.cve.org

6.5 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

0.001 Low

EPSS

Percentile

40.7%

JSON

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.

CNA Affected

[
  {
    "product": "ckeditor5",
    "vendor": "ckeditor",
    "versions": [
      {
        "status": "affected",
        "version": "< 25.0.0"
      }
    ]
  }
]