CVE-2021-43827
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…
Does this matter?
Lower severity and a low EPSS score (0.80%). Track it; it rarely justifies an emergency change on its own.
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 3.1
- 4.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
- EPSS
- 0.80% probability · 55th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-755
- Affected
- discourse/discourse footnote
- Source
- security-advisories@github.com
References
- https://github.com/discourse/discourse-footnote/commit/796617e0131277011207541313522cd1946661abPatch, Third Party Advisory
- https://github.com/discourse/discourse-footnote/security/advisories/GHSA-58vr-c56v-qr57Third Party Advisory
- https://github.com/discourse/discourse-footnote/commit/796617e0131277011207541313522cd1946661abPatch, Third Party Advisory
- https://github.com/discourse/discourse-footnote/security/advisories/GHSA-58vr-c56v-qr57Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.