system
Provide references for <CVE-2021-3987>.
user
Where can I find more information about <CVE-2021-3987>?
assistant
References are available at: https://huntr.com/bounties/29fcc091-87b6-43bc-ab4b-3c0bec3f71df, https://github.com/janeczku/calibre-web/commit/bcdc97641447965af486964537f3821f47b28874.