RHSA-2020:3274 — Security Advisory

An update for grub2, shim, shim-signed, and fwupdate is now available for Red Hat Enterprise Linux 7.7 Extended Update Support.

Red Hat Product Security has rated this update as having a security impact of Moderate. 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.

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.

The fwupdate packages provide a service that allows session software to update device firmware.

Security Fix(es):

• grub2: Crafted grub.cfg file can lead to arbitrary code execution during boot process (CVE-2020-10713)

• grub2: grub_malloc does not validate allocation size allowing for arithmetic overflow and subsequent heap-based buffer overflow (CVE-2020-14308)

• grub2: Integer overflow in grub_squash_read_symlink may lead to heap-based buffer overflow (CVE-2020-14309)

• grub2: Integer overflow read_section_as_string may lead to heap-based buffer overflow (CVE-2020-14310)

• grub2: Integer overflow in grub_ext2_read_link leads to heap-based buffer overflow (CVE-2020-14311)

• grub2: Fail kernel validation without shim protocol (CVE-2020-15705)

• grub2: Use-after-free redefining a function whilst the same function is already executing (CVE-2020-15706)

• grub2: Integer overflow in initrd size handling (CVE-2020-15707)

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.

Bug Fix(es):

• grub2 should get resynced with 7.8 branch (BZ#1861855)