Das U-Boot through 2020.01 allows attackers to bypass verified boot restrictions and subsequently boot arbitrary images by providing a crafted FIT image to a system configured to boot the default configuration.
https://labs.f-secure.com/advisories/das-u-boot-verified-boot-bypass/
https://github.com/u-boot/u-boot/commits/master
http://www.openwall.com/lists/oss-security/2020/03/18/5
http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00030.html