GHSA-HGMG-HHC8-G5WR
Vulnerability from github – Published: 2021-01-29 21:51 – Updated: 2022-08-11 18:16Impact
A regular expression denial of service (ReDoS) vulnerability has been discovered in the CKEditor 5 Markdown plugin code. The vulnerability allowed to abuse a link recognition regular expression, which could cause a significant performance drop resulting in a browser tab freeze. It affects all users using the CKEditor 5 Markdown plugin at version <= 24.0.0.
Patches
The problem has been recognized and patched. The fix will be available in version 25.0.0.
Workarounds
The user can work around the issue by: - Upgrading CKEditor 5 to version 25.0.0. - Disabling the Markdown plugin.
More information
If you have any questions or comments about this advisory: * Email us at security@cksource.com
Acknowledgements
The CKEditor 5 team would like to thank Erik Krogh Kristensen from the GitHub team for recognizing this vulnerability and Alvaro Muñoz from GitHub for reporting it.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 24.0.0"
},
"package": {
"ecosystem": "npm",
"name": "@ckeditor/ckeditor5-markdown-gfm"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "25.0.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-21254"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2021-01-29T21:50:43Z",
"nvd_published_at": "2021-01-29T22:15:00Z",
"severity": "MODERATE"
},
"details": "### Impact\nA regular expression denial of service (ReDoS) vulnerability has been discovered in the CKEditor 5 Markdown plugin code. The vulnerability allowed to abuse a link recognition regular expression, which could cause a significant performance drop resulting in a browser tab freeze. It affects all users using the CKEditor 5 Markdown plugin at version \u003c= 24.0.0. \n\n### Patches\nThe problem has been recognized and patched. The fix will be available in version 25.0.0.\n\n### Workarounds\nThe user can work around the issue by:\n- Upgrading CKEditor 5 to version 25.0.0.\n- Disabling the Markdown plugin.\n\n### More information\nIf you have any questions or comments about this advisory:\n* Email us at [security@cksource.com](mailto:security@cksource.com)\n\n### Acknowledgements\nThe CKEditor 5 team would like to thank Erik Krogh Kristensen from the GitHub team for recognizing this vulnerability and \nAlvaro Mu\u00f1oz from GitHub for reporting it.",
"id": "GHSA-hgmg-hhc8-g5wr",
"modified": "2022-08-11T18:16:15Z",
"published": "2021-01-29T21:51:22Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-hgmg-hhc8-g5wr"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-21254"
},
{
"type": "PACKAGE",
"url": "https://github.com/ckeditor/ckeditor5"
},
{
"type": "WEB",
"url": "https://github.com/ckeditor/ckeditor5/releases/tag/v25.0.0"
},
{
"type": "WEB",
"url": "https://www.npmjs.com/package/@ckeditor/ckeditor5-markdown-gfm"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "CKEditor 5 Markdown plugin Regular expression Denial of Service"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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