Moderate: grub2 security and bug fix update

Topic

An update for grub2 is now available for Red Hat Enterprise Linux 8.6 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.

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.

Security Fix(es):

• grub2: Buffer overflow in grub_font_construct_glyph() can lead to out-of-bound write and possible secure boot bypass (CVE-2022-2601)
• grub2: Heap based out-of-bounds write when redering certain unicode sequences (CVE-2022-3775)

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):

• [RHEL8.6][SecureBoot][Denali/P10] boot process stops at grub prompt after copying the signed grub to prep partition (BZ#2108049)

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

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

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 8.6 x86_64
• Red Hat Enterprise Linux Server - AUS 8.6 x86_64
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 8.6 ppc64le
• Red Hat Enterprise Linux Server - TUS 8.6 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 8.6 aarch64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 8.6 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 8.6 x86_64

Fixes

• BZ - 2112975 - CVE-2022-2601 grub2: Buffer overflow in grub_font_construct_glyph() can lead to out-of-bound write and possible secure boot bypass
• BZ - 2138880 - CVE-2022-3775 grub2: Heap based out-of-bounds write when redering certain unicode sequences

CVEs

• CVE-2022-2601
• CVE-2022-3775

References

• https://access.redhat.com/security/updates/classification/#moderate