11 shims. Still trusted.
Per SecurityWeek, these vulnerable UEFI shim bootloaders, signed by Microsoft, could be abused on any system, regardless of the OS, as reported by Dark Reading, which notes nearly a dozen remained trusted for years. The Hacker News details that cybersecurity researchers discovered these 11 old, Microsoft-signed applications that could be abused to bypass Secure Boot, enabling deployment of malicious UEFI bootkits or other malware, as also confirmed by Matrice Digitale, which states ESET found these shims allow for the installation of persistent bootkits.
While many view Secure Boot as a robust security feature, the reality is that forgotten bootloaders expose a significant blind spot, as highlighted by the fact that these vulnerable shims were trusted for years, per Dark Reading. As The Hacker News and SecurityWeek both report, an attacker exploiting one of these vulnerable applications can execute untrusted code during system boot. According to Matrice Digitale, this allows for the bypass of Secure Boot and the installation of persistent bootkits, with SecurityWeek noting this affects systems regardless of the OS.
The defensive math: -> Review your Secure Boot configurations to ensure only trusted bootloaders are in use, as recommended by The Hacker News -> Rotate and revoke any outdated or vulnerable UEFI shims, as advised by Dark Reading and SecurityWeek -> Implement a robust firmware security strategy, including regular updates and secure boot validation, as suggested by Matrice Digitale and The Hacker News, to prevent similar bypasses in the future
What steps will you take to address the Secure Boot blind spot exposed by these vulnerable UEFI shims?