Provide references for CVE-2021-3271.
Where can I find more information about CVE-2021-3271?
References are available at: https://github.com/pressbooks/pressbooks/pull/2072, https://github.com/pressbooks/pressbooks, https://www.gosecure.net/blog/2021/02/16/cve-2021-3271-pressbooks-stored-cross-site-scripting-proof-of-concept/.