RHSA-2024:1959: Important: shim security update

The shim package contains a first-stage UEFI boot loader that handles chaining<br>to a trusted full boot loader under secure boot environments.<br>Security Fix(es):<br><li> shim: RCE in http boot support may lead to Secure Boot bypass (CVE-2023-40547)</li> <li> shim: Interger overflow leads to heap buffer overflow in verifysbatsection on 32-bits systems (CVE-2023-40548)</li> <li> shim: Out-of-bounds read printing error messages (CVE-2023-40546)</li> <li> shim: Out-of-bounds read in verifybufferauthenticode() malformed PE file (CVE-2023-40549)</li> <li> shim: Out-of-bound read in verifybuffersbat() (CVE-2023-40550)</li> <li> shim: out of bounds read when parsing MZ binaries (CVE-2023-40551)</li> For more details about the security issue(s), including the impact, a CVSS<br>score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.<br>IMPORTANT: The new shim revokes ALL VERSIONS of GRUB2 before grub2-2.02-0.87.el79.14. Therefore GRUB2 MUST be updated to the latest<br>version: grub2-2.02-0.87.el79.14 BEFORE or SIMULTANEOUSLY with this shim in order for Secure Boot to continue to work. Failure to update GRUB2 will result in an UNBOOTABLE system.

— Red Hat