Provide references for CVE-2019-20421.
Where can I find more information about CVE-2019-20421?
References are available at: https://github.com/Exiv2/exiv2/issues/1011, https://github.com/Exiv2/exiv2/commit/a82098f4f90cd86297131b5663c3dec6a34470e8, https://usn.ubuntu.com/4270-1/, https://www.debian.org/security/2021/dsa-4958, https://lists.debian.org/debian-lts-announce/2021/08/msg00028.html.