Provide references for CVE-2019-18978.
Where can I find more information about CVE-2019-18978?
References are available at: https://github.com/cyu/rack-cors/commit/e4d4fc362a4315808927011cbe5afcfe5486f17d, https://github.com/cyu/rack-cors/compare/v1.0.3...v1.0.4, https://lists.debian.org/debian-lts-announce/2020/02/msg00004.html, https://lists.debian.org/debian-lts-announce/2020/10/msg00000.html, https://usn.ubuntu.com/4571-1/, https://www.debian.org/security/2021/dsa-4918.