CVE-2021-29503
HedgeDoc before version 1.8.2 is vulnerable to a cross-site scripting attack using the YAML-metadata of a note.
Does this matter?
Lower severity and a low EPSS score (1.04%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 1.04% probability · 62th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-80, CWE-79
- Affected
- hedgedoc/hedgedoc
- Source
- security-advisories@github.com
References
- https://github.com/hedgedoc/hedgedoc/commit/01dad5821ee28377ebe640c6c72c3e0bb0d51ea7Patch, Third Party Advisory
- https://github.com/hedgedoc/hedgedoc/releases/tag/1.8.2Third Party Advisory
- https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-gjg7-4j2h-94fqPatch, Third Party Advisory
- https://github.com/hedgedoc/hedgedoc/commit/01dad5821ee28377ebe640c6c72c3e0bb0d51ea7Patch, Third Party Advisory
- https://github.com/hedgedoc/hedgedoc/releases/tag/1.8.2Third Party Advisory
- https://github.com/hedgedoc/hedgedoc/security/advisories/GHSA-gjg7-4j2h-94fqPatch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.