Recommended update for shim

The shim component has been updated to versions 16.0 and 16.1 to fix several issues. Notably, CVE-2024-2312 is addressed by adding grub.peimage,2 to the SBAT metadata, which helps in tracking and mitigating vulnerabilities in GRUB. Other fixes include correcting protocol handling, memory allocation issues, IPv6 netboot fixes, loader protocol improvements, and enhancements to security features such as Authenticode signing and enforcement of NX policies. The update also improves error handling and logging related to secure boot and MOK management.

The vulnerabilities fixed by this update, including CVE-2024-2312, relate to secure boot and bootloader integrity mechanisms. These issues could potentially allow bypass or weakening of secure boot protections if left unpatched. However, there are no reports of known exploits in the wild. The impact is medium severity given the role of shim in the secure boot chain and the nature of the fixes.

Apply the shim update to versions 16.0 and 16.1 as provided by the vendor to address these issues. Since this is an official update fixing multiple security and stability issues including CVE-2024-2312, upgrading to the patched versions is the recommended remediation. No additional mitigation steps are indicated beyond applying the update.