11 Old Microsoft-Signed UEFI Shims Let Attackers Bypass Secure Boot

Researchers found 11 old Microsoft-signed UEFI shims that can be exploited to bypass Secure Boot on most modern systems. Attackers can use these to execute untrusted code during boot, deploying bootkits or other malware. The vulnerabilities stem from outdated shims that were once signed by Microsoft but are no longer secure.