CVE-2022-3775

When rendering certain unicode sequences, grub2's font code doesn't proper validate if the informed glyph's width and height is constrained within bitmap size. As consequence an attacker can craft an input which will lead to a out-of-bounds write into grub2's heap, leading to memory corruption and availability issues. Although complex, arbitrary code execution could not be discarded.

GNU GRUB is a Multiboot boot loader. It was derived from GRUB, the GRand Unified Bootloader, which was originally designed and implemented by Erich Stefan Boleyn.Briefly, a boot loader is the first software program that runs when a computer starts. It is responsible for loading and transferring control to the operating system kernel software (such as the Hurd or Linux). The kernel, in turn, initializes the rest of the operating system (e.g. GNU).

Security Fix(es):

A flaw was found where a maliciously crafted pf2 font could lead to an out-of-bounds write in grub2. A successful attack can lead to memory corruption and secure boot circumvention.(CVE-2022-2601)

A flaw was found in the grub2 font code. When rendering certain unicode sequences, it fails to properly validate the font width and height. These values are further used to access the font buffer, causing possible out-of-bounds writes. A malicious actor may craft a font capable of triggering this issue, allowing modifications in unauthorized memory segments, causing data integrity problems or leading to denial of service.(CVE-2022-3775)

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.

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.

When rendering certain unicode sequences, grub2's font code doesn't proper validate if the informed glyph's width and height is constrained within bitmap size. As consequence an attacker can craft an input which will lead to a out-of-bounds write into grub2's heap, leading to memory corruption and availability issues. Although complex, arbitrary code execution could not be discarded.

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.

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.

• font: Reject glyphs exceeds font->max_glyph_width or font->max_glyph height
• font: Fix size overflow in grub_font_get_glyph_internal()
• CVE-2022-2601: font: Fix several integer overflows in grub_font_construct_glyph()
• CVE-2022-3775: font: Fix an integer underflow in blit_comb()

• font: Reject glyphs exceeds font->max_glyph_width or font->max_glyph height
• font: Fix size overflow in grub_font_get_glyph_internal()
• CVE-2022-2601: font: Fix several integer overflows in grub_font_construct_glyph()
• CVE-2022-3775: font: Fix an integer underflow in blit_comb()

• Fix package version number
• Use CloudLinux vendor cert
• Make this package installable only on a system having Cloudlinux signed components: grub2 and kernel
• Add patches from centos-8.5 ELS:
• CVE-2021-3695: out-of-bounds write in the heap area by a crafted 16-bit grayscale PNG image
• CVE-2021-3696: a heap out-of-bounds during the handling of Huffman tables in the PNG reader
• CVE-2021-3697: allowing user-controlled data to be written in heap by a crafted JPEG image
• CVE-2022-2601: possible circumventing of the secure boot mechanism by a malicious crafted pf2 font
• CVE-2022-28733: possible write past the end of the buffer because of integer underflow in grub_net_recv_ip4_packets()
• CVE-2022-28734: out-of-bounds write when handling split HTTP headers
• CVE-2022-28736: use-after-free vulnerability in grub_cmd_chainloader()
• CVE-2022-3775: out-of-bounds write into grub2’s heap because of lack of proper validation of glyph’s width and height
• CVE-2023-4692: out-of-bounds write in grub2’s NTFS filesystem driver
• The following CVEs were fixed by previous patches additionally:
• CVE-2020-15706: a race condition in grub_script_function_create() leading to a use-after-free vulnerability
• CVE-2020-15707: integer overflows in efilinux leading to a heap-based buffer overflow
• A number of upstream fixes backported including:
• CVE-2024-1048: a flaw that may result in filesystem running out of free inodes or blocks

When rendering certain unicode sequences, grub2's font code doesn't proper validate if the informed glyph's width and height is constrained within bitmap size. As consequence an attacker can craft an input which will lead to a out-of-bounds write into grub2's heap, leading to memory corruption and availability issues. Although complex, arbitrary code execution could not be discarded.

These are all security issues fixed in the grub2-2.06-31.1 package on the GA media of openSUSE Tumbleweed.

This update for grub2 fixes the following issues:

• CVE-2022-2601: Fixed buffer overflow in grub_font_construct_glyph (bsc#1205178).
• CVE-2022-3775: Fixed integer underflow in blit_comb() (bsc#1205182).

Other:

• Bump upstream SBAT generation to 3

This update for grub2 fixes the following issues:

• CVE-2022-2601: Fixed buffer overflow in grub_font_construct_glyph (bsc#1205178).
• CVE-2022-3775: Fixed integer underflow in blit_comb() (bsc#1205182).

Other:

• Bump upstream SBAT generation to 3

This update for grub2 fixes the following issues:

Security Fixes:

• CVE-2022-2601: Fixed buffer overflow in grub_font_construct_glyph (bsc#1205178).
• CVE-2022-3775: Fixed integer underflow in blit_comb() (bsc#1205182).

Other:

• Bump upstream SBAT generation to 3

This update for grub2 fixes the following issues:

Security Fixes:

• CVE-2022-2601: Fixed buffer overflow in grub_font_construct_glyph (bsc#1205178).
• CVE-2022-3775: Fixed integer underflow in blit_comb() (bsc#1205182).

Other:

• Bump upstream SBAT generation to 3

This update for grub2 fixes the following issues:

Security Fixes:

• CVE-2022-2601: Fixed buffer overflow in grub_font_construct_glyph (bsc#1205178).
• CVE-2022-3775: Fixed integer underflow in blit_comb() (bsc#1205182).

Other:

• Bump upstream SBAT generation to 3

This update for grub2 fixes the following issues:

• CVE-2022-2601: Fixed buffer overflow in grub_font_construct_glyph (bsc#1205178).
• CVE-2022-3775: Fixed integer underflow in blit_comb() (bsc#1205182).

Other:

• Bump upstream SBAT generation to 3

This update for grub2 fixes the following issues:

• CVE-2022-2601: Fixed buffer overflow in grub_font_construct_glyph (bsc#1205178).
• CVE-2022-3775: Fixed integer underflow in blit_comb() (bsc#1205182).

Other:

• Bump upstream SBAT generation to 3

This update for grub2 fixes the following issues:

Security Fixes:

• CVE-2022-2601: Fixed buffer overflow in grub_font_construct_glyph (bsc#1205178).
• CVE-2022-3775: Fixed integer underflow in blit_comb() (bsc#1205182).

Other:

• Bump upstream SBAT generation to 3
• Fix unreadable filesystem with xfs v4 superblock (bsc#1205520).
• Remove zfs modules (bsc#1205554).

This security update of grub2 fixes the following issues:

• CVE-2022-2601: Fixed buffer overflow in grub_font_construct_glyph (bsc#1205178).

• CVE-2022-3775: Fixed integer underflow in blit_comb() (bsc#1205182).

• Bump upstream SBAT generation to 3

• rebuild the package with the new secure boot key (bsc#1209188).

Other:

• Remove zfs modules (bsc#1205554)
• Make grub.cfg invariant to efi and legacy platforms (bsc#1205200)

Daniel Axtens discovered that specially crafted images could cause a heap-based out-of-bonds write. A local attacker could possibly use this to circumvent secure boot protections. (CVE-2021-3695)

Daniel Axtens discovered that specially crafted images could cause out-of-bonds read and write. A local attacker could possibly use this to circumvent secure boot protections. (CVE-2021-3696)

Daniel Axtens discovered that specially crafted images could cause buffer underwrite which allows arbitrary data to be written to a heap. A local attacker could possibly use this to circumvent secure boot protections. (CVE-2021-3697)

It was discovered that GRUB2 configuration files were created with the wrong permissions. An attacker could possibly use this to leak encrypted passwords. (CVE-2021-3981)

Daniel Axtens discovered that specially crafted IP packets could cause an integer underflow and write past the end of a buffer. An attacker could possibly use this to circumvent secure boot protections. (CVE-2022-28733)

Daniel Axtens discovered that specially crafted HTTP headers can cause an out-of-bounds write of a NULL byte. An attacker could possibly use this to corrupt GRUB2's internal data. (CVE-2022-28734)

Julian Andres Klode discovered that GRUB2 shim_lock allowed non- kernel files to be loaded. A local attack could possibly use this to circumvent secure boot protections. (CVE-2022-28735)

Chris Coulson discovered that executing chainloaders more than once caused a use-after-free vulnerability. A local attack could possibly use this to circumvent secure boot protections. (CVE-2022-28736)

Chris Coulson discovered that specially crafted executables could cause shim to make out-of-bound writes. A local attack could possibly use this to circumvent secure boot protections. (CVE-2022-28737)

Zhang Boyang discovered that specially crafted unicode sequences could lead to an out-of-bounds write to a heap. A local attacker could possibly use this to circumvent secure boot protections. (CVE-2022-3775)