Issued:
2024-04-23
Updated:
2024-04-23

RHSA-2024:1959 - Important: shim security update

Synopsis

Important: shim security update

Type/Severity

Security Advisory Important

Topic

An update for shim is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The shim package contains a first-stage UEFI boot loader that handles chaining to a trusted full boot loader under secure boot environments.

Security Fix(es):

  • shim: RCE in http boot support may lead to Secure Boot bypass (CVE-2023-40547)

  • shim: Interger overflow leads to heap buffer overflow in verify_sbat_section on 32-bits systems (CVE-2023-40548)

  • shim: Out-of-bounds read printing error messages (CVE-2023-40546)

  • shim: Out-of-bounds read in verify_buffer_authenticode() malformed PE file (CVE-2023-40549)

  • shim: Out-of-bound read in verify_buffer_sbat() (CVE-2023-40550)

  • shim: out of bounds read when parsing MZ binaries (CVE-2023-40551)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

IMPORTANT: The new shim revokes ALL VERSIONS of GRUB2 before grub2-2.02-0.87.el7_9.14. Therefore GRUB2 MUST be updated to the latest version: grub2-2.02-0.87.el7_9.14 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.

Solution

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

ProductVersionArch
Red Hat Enterprise Linux for Scientific Computing7x86_64
Red Hat Enterprise Linux Workstation7x86_64
Red Hat Enterprise Linux Server7x86_64
Red Hat Enterprise Linux Server - Extended Life Cycle Support7x86_64
Red Hat Enterprise Linux Desktop7x86_64

Updated Packages

  • shim-15.8-3.el7.src.rpm
  • mokutil-debuginfo-15.8-1.el7.x86_64.rpm
  • shim-unsigned-x64-15.8-3.el7.x86_64.rpm
  • mokutil-15.8-1.el7.x86_64.rpm
  • shim-x64-15.8-1.el7.x86_64.rpm
  • shim-unsigned-ia32-15.8-3.el7.x86_64.rpm
  • shim-ia32-15.8-1.el7.x86_64.rpm
  • shim-signed-15.8-1.el7.src.rpm

Fixes

CVEs

References

Additional information