Vulnerabilities > CVE-2021-43827 - Improper Handling of Exceptional Conditions vulnerability in Discourse Footnote 0.1
Attack vector
NETWORK Attack complexity
LOW Privileges required
SINGLE Confidentiality impact
NONE Integrity impact
NONE Availability impact
PARTIAL Summary
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.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 1 |