Provide references for CVE-2021-3944.
Where can I find more information about CVE-2021-3944?
References are available at: https://huntr.dev/bounties/65551490-5ade-49aa-8b8d-274c2ca9fdc9, https://github.com/bookstackapp/bookstack/commit/88e6f93abf54192a69cc8080e0dc6516ee68ccbb.