Provide references for CVE-2021-28688.
Where can I find more information about CVE-2021-28688?
References are available at: https://xenbits.xenproject.org/xsa/advisory-371.txt, https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html, https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html.