RHSA-2022:5098 — Security Advisory
Red Hat Security Advisory: grub2, mokutil, and shim security update
Severity
ImportantRed Hat Product Security
Products
Official CSAF product identity
Published · June 16, 2022
Updated · June 27, 2026
Topic
An update for grub2, mokutil, and shim is now available for Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions.
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 grub2 packages provide version 2 of the Grand Unified Boot Loader (GRUB), a highly configurable and customizable boot loader with modular architecture. The packages support a variety of kernel formats, file systems, computer architectures, and hardware devices.
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):
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grub2: Integer underflow in grub_net_recv_ip4_packets (CVE-2022-28733)
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grub2: Crafted PNG grayscale images may lead to out-of-bounds write in heap (CVE-2021-3695)
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grub2: Crafted PNG image may lead to out-of-bound write during huffman table handling (CVE-2021-3696)
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grub2: Crafted JPEG image can lead to buffer underflow write in the heap (CVE-2021-3697)
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grub2: Out-of-bound write when handling split HTTP headers (CVE-2022-28734)
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grub2: shim_lock verifier allows non-kernel files to be loaded (CVE-2022-28735)
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grub2: use-after-free in grub_cmd_chainloader() (CVE-2022-28736)
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shim: Buffer overflow when loading crafted EFI images (CVE-2022-28737)
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.