Potocki claims that MSI's firmware update version' 7C02v3C,' released on January 18, 2022, changed a default Secure Boot setting on MSI motherboards so that the system will boot even if it detects security violations.
"I decided to setup Secure Boot on my new desktop with the help of sbctl. Unfortunately, I have found that my firmware was accepting every OS image I gave it, no matter if it was trusted or not," explains the researcher in his writeup.
"As I have later discovered on 2022-12-16, it wasn't just broken firmware; MSI had changed their Secure Boot defaults to allow booting on security violations(!!)."
Potocki explains that users should set the Execution Policy to "Deny Execute" for "Removable Media" and "Fixed Media," which should only allow signed software to boot.
A complete list of the over 290 motherboards affected by this insecure setting is available on GitHub.
Personal note: Windows users w/certain MSI boards who can't update to 11 might be esp. interested. According to the Bleeping article, MSI has not yet responded with an answer on how it plans to address this issue.