Recent findings have identified two vulnerabilities in various UEFI BIOS versions from multiple manufacturers, compromising the SecureBoot mechanism. These vulnerabilities allow attackers to bypass SecureBoot protections and replace firmware, particularly in Insyde BIOSes. The issues stem from unprotected NVRAM variables, specifically the "IhisiParamBuffer," which can be manipulated to execute unsigned UEFI binaries. Affected UEFI applications include "DTBios" and "BiosFlashShell" from DTResearch, with a CVSS score of 8.2. Microsoft has added 14 new hashes to its DBX database to mitigate these risks.
Additionally, a vulnerability in the Insyde H2O UEFI firmware app allows attackers to infiltrate digital certificates due to the insecure handling of the "SecureFlashCertData" variable, which is incorrectly treated as trusted memory. This flaw, known as "Hydroph0bia," has a CVSS score of 7.8 and enables unauthorized execution of firmware certified with manipulated certificates. Manufacturers are urged to provide firmware updates to address these vulnerabilities, as inconsistent support for locking UEFI variables raises security concerns.