It appears that the source code for AMI Aptio UEFI BIOS that includes the AMI unique UEFI signing test key has leaked on an unsecured FTP server in Taiwan thus compromising the security of every motherboard that runs on that BIOS.


Since the AMI Aptio UEFI BIOS can be found on most LGA1155 socket and FM2 socket motherboards as well as on some AM3+ socket motherboard, the leaked BIOS source code and the unique UEFI signing test key pose a quite a serious security problem. The key is used so that BIOS update software can verify that the update is genuine and actually comes from the motherboard manufacturer and not some other third party.


Now that the key has leaked online, malware developers can use it to deliver malicious BIOS updates gaining control access and creating a nearly undetectable and permanent hole in system security.


It is still not clear if vendors are using the same key for other products which could make things even worse and not localized to motherboards.



Source: Techpowerup.com