CVE-2021-43827

Date: December 14, 2021

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.

Language: JS