Vulnerability Description
HedgeDoc is a platform to write and share markdown. HedgeDoc before version 1.8.2 is vulnerable to a cross-site scripting attack using the YAML-metadata of a note. An attacker with write access to a note can embed HTML tags in the Open Graph metadata section of the note, resulting in the frontend rendering the script tag as part of the `<head>` section. Unless your instance prevents guests from editing notes, this vulnerability allows unauthenticated attackers to inject JavaScript into notes that allow guest edits. If your instance prevents guests from editing notes, this vulnerability allows authenticated attackers to inject JavaScript into any note pages they have write-access to. This vulnerability is patched in version 1.8.2. As a workaround, one can disable guest edits until the next update.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Hedgedoc | Hedgedoc | < 1.8.2 |
Related Weaknesses (CWE)
References
- https://github.com/hedgedoc/hedgedoc/commit/01dad5821ee28377ebe640c6c72c3e0bb0d5PatchThird Party Advisory
- https://github.com/hedgedoc/hedgedoc/releases/tag/1.8.2Third Party Advisory
- https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-gjg7-4j2h-94fqPatchThird Party Advisory
- https://github.com/hedgedoc/hedgedoc/commit/01dad5821ee28377ebe640c6c72c3e0bb0d5PatchThird Party Advisory
- https://github.com/hedgedoc/hedgedoc/releases/tag/1.8.2Third Party Advisory
- https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-gjg7-4j2h-94fqPatchThird Party Advisory
FAQ
What is CVE-2021-29503?
CVE-2021-29503 is a vulnerability with a CVSS score of 8.1 (HIGH). HedgeDoc is a platform to write and share markdown. HedgeDoc before version 1.8.2 is vulnerable to a cross-site scripting attack using the YAML-metadata of a note. An attacker with write access to a n...
How severe is CVE-2021-29503?
CVE-2021-29503 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-29503?
Check the references section above for vendor advisories and patch information. Affected products include: Hedgedoc Hedgedoc.