Provide references for CVE-2021-3964.
Where can I find more information about CVE-2021-3964?
References are available at: https://huntr.dev/bounties/a4df45d6-b739-4299-967f-c960b569383a, https://github.com/elgg/elgg/commit/d9fcad76ee380ea17edd61d13d0f87828ea3f744.