Vulnerability Description
discourse-footnote is a library providing footnotes for posts in Discourse. ### Impact When posting an inline footnote wrapped in `<a>` tags (e.g. `<a>^[footnote]</a>`, the resulting rendered HTML would include a nested `<a>`, which is stripped by Nokogiri because it is not valid. This then caused a javascript error on topic pages because we were looking for an `<a>` element inside the footnote reference span and getting its ID, and because it did not exist we got a null reference error in javascript. Users are advised to update to version 0.2. As a workaround editing offending posts from the rails console or the database console for self-hosters, or disabling the plugin in the admin panel can mitigate this issue.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Discourse | Discourse Footnote | < 0.2 |
Related Weaknesses (CWE)
References
- https://github.com/discourse/discourse-footnote/commit/796617e013127701120754131PatchThird Party Advisory
- https://github.com/discourse/discourse-footnote/security/advisories/GHSA-58vr-c5Third Party Advisory
- https://github.com/discourse/discourse-footnote/commit/796617e013127701120754131PatchThird Party Advisory
- https://github.com/discourse/discourse-footnote/security/advisories/GHSA-58vr-c5Third Party Advisory
FAQ
What is CVE-2021-43827?
CVE-2021-43827 is a vulnerability with a CVSS score of 4.3 (MEDIUM). discourse-footnote is a library providing footnotes for posts in Discourse. ### Impact When posting an inline footnote wrapped in `<a>` tags (e.g. `<a>^[footnote]</a>`, the resulting rendered HTML wou...
How severe is CVE-2021-43827?
CVE-2021-43827 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-43827?
Check the references section above for vendor advisories and patch information. Affected products include: Discourse Discourse Footnote.