CVE-2023-4692

An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. This issue may allow an attacker to present a specially crafted NTFS filesystem image, leading to grub's heap metadata corruption. In some circumstances, the attack may also corrupt the UEFI firmware heap metadata. As a result, arbitrary code execution and secure boot protection bypass may be achieved.

An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. This issue may allow an attacker to present a specially crafted NTFS filesystem image, leading to grub's heap metadata corruption. In some circumstances, the attack may also corrupt the UEFI firmware heap metadata. As a result, arbitrary code execution and secure boot protection bypass may be achieved.

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.

Security Fix(es):

An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. This issue may allow an attacker to present a specially crafted NTFS filesystem image, leading to grub's heap metadata corruption. In some circumstances, the attack may also corrupt the UEFI firmware heap metadata. As a result, arbitrary code execution and secure boot protection bypass may be achieved.(CVE-2023-4692)

An out-of-bounds read flaw was found on grub2's NTFS filesystem driver. This issue may allow a physically present attacker to present a specially crafted NTFS file system image to read arbitrary memory locations. A successful attack allows sensitive data cached in memory or EFI variable values to be leaked, presenting a high Confidentiality risk.(CVE-2023-4693)

An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. This issue may allow an attacker to present a specially crafted NTFS filesystem image, leading to grub's heap metadata corruption. In some circumstances, the attack may also corrupt the UEFI firmware heap metadata. As a result, arbitrary code execution and secure boot protection bypass may be achieved.

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: grub2-set-bootflag can be abused by local (pseudo-)users (CVE-2024-1048)
• grub2: Out-of-bounds write at fs/ntfs.c may lead to unsigned code execution (CVE-2023-4692)
• grub2: out-of-bounds read at fs/ntfs.c (CVE-2023-4693)

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.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from 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: grub2-set-bootflag can be abused by local (pseudo-)users (CVE-2024-1048)
• grub2: Out-of-bounds write at fs/ntfs.c may lead to unsigned code execution (CVE-2023-4692)
• grub2: out-of-bounds read at fs/ntfs.c (CVE-2023-4693)

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.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

• CVE-2023-4692: ntfs: checks to ensure that NTFS drive's sector numbers are never written beyond the boundary

• CVE-2023-4692: ntfs: checks to ensure that NTFS drive's sector numbers are never written beyond the boundary

• CVE-2023-4692: ntfs: checks to ensure that NTFS drive's sector numbers are never written beyond the boundary

• CVE-2023-4692: ntfs: checks to ensure that NTFS drive's sector numbers are never written beyond the boundary
• CVE-2023-4693: ntfs: fix an out-of-bounds read flaw on NTFS filesystem driver

• 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

• Sign by Cloudlinux
• CVE-2023-4692: ntfs: checks to ensure that NTFS drive's sector numbers are never written beyond the boundary
• CVE-2023-4693: ntfs: fix an out-of-bounds read flaw on NTFS filesystem driver

• CVE-2023-4692: fix OOB write when parsing NTFS $ATTRIBUTE_LIST entries

An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. This issue may allow an attacker to present a specially crafted NTFS filesystem image, leading to grub's heap metadata corruption. In some circumstances, the attack may also corrupt the UEFI firmware heap metadata. As a result, arbitrary code execution and secure boot protection bypass may be achieved. (CVE-2023-4692) An out-of-bounds read flaw was found on grub2's NTFS filesystem driver. This issue may allow a physically present attacker to present a specially crafted NTFS file system image to read arbitrary memory locations. A successful attack allows sensitive data cached in memory or EFI variable values to be leaked, presenting a high Confidentiality risk. (CVE-2023-4693) An authentication bypass flaw was found in GRUB due to the way that GRUB uses the UUID of a device to search for the configuration file that contains the password hash for the GRUB password protection feature. An attacker capable of attaching an external drive such as a USB stick containing a file system with a duplicate UUID (the same as in the "/boot/" file system) can bypass the GRUB password protection feature on UEFI systems, which enumerate removable drives before non-removable ones. (CVE-2023-4001) A flaw was found in the grub2-set-bootflag utility of grub2. After the fix of CVE-2019-14865, grub2-set-bootflag will create a temporary file with the new grubenv content and rename it to the original grubenv file. If the program is killed before the rename operation, the temporary file will not be removed and may fill the filesystem when invoked multiple times, resulting in a filesystem out of free inodes or blocks. (CVE-2024-1048)

These are all security issues fixed in the grub2-2.12~rc1-5.1 package on the GA media of openSUSE Tumbleweed.

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: grub2-set-bootflag can be abused by local (pseudo-)users (CVE-2024-1048)

• grub2: Out-of-bounds write at fs/ntfs.c may lead to unsigned code execution (CVE-2023-4692)

• grub2: out-of-bounds read at fs/ntfs.c (CVE-2023-4693)

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.

Additional Changes:

For detailed information on changes in this release, see the Rocky Linux 8.10 Release Notes linked from the References section.

This update for grub2 fixes the following issues:

Security fixes:

• CVE-2023-4692: Fixed an out-of-bounds write at fs/ntfs.c which may lead to unsigned code execution. (bsc#1215935)
• CVE-2023-4693: Fixed an out-of-bounds read at fs/ntfs.c which may lead to leak sensitive information. (bsc#1215936)

Other fixes:

• Fix 'command not found' error of grub2-once (bsc#1204563, bsc#1215382)

This update for grub2 fixes the following issues:

• CVE-2023-4692: Fixed an out-of-bounds write at fs/ntfs.c which may lead to unsigned code execution. (bsc#1215935)
• CVE-2023-4693: Fixed an out-of-bounds read at fs/ntfs.c which may lead to leak sensitive information. (bsc#1215936)

This update for grub2 fixes the following issues:

Security fixes:

• CVE-2023-4692: Fixed an out-of-bounds write at fs/ntfs.c which may lead to unsigned code execution. (bsc#1215935)
• CVE-2023-4693: Fixed an out-of-bounds read at fs/ntfs.c which may lead to leak sensitive information. (bsc#1215936)

Other fixes:

• Fix a boot delay issue in PowerPC PXE boot (bsc#1201300)

This update for grub2 fixes the following issues:

Security fixes:

• CVE-2023-4692: Fixed an out-of-bounds write at fs/ntfs.c which may lead to unsigned code execution. (bsc#1215935)
• CVE-2023-4693: Fixed an out-of-bounds read at fs/ntfs.c which may lead to leak sensitive information. (bsc#1215936)

Other fixes:

• Fix a boot delay issue in PowerPC PXE boot (bsc#1201300)

This update for grub2 fixes the following issues:

• CVE-2023-4692: nfs: out-of-bounds write at fs/ntfs.c may lead to unsigned code execution (bsc#1215935).
• CVE-2023-4693: nfs: out-of-bounds read at fs/ntfs.c (bsc#1215936).
• CVE-2024-45774: heap overflows in JPEG parser (bsc#1233609).
• CVE-2024-45775: missing NULL check in extcmd parser (bsc#1233610).
• CVE-2024-45776: overflow in .MO file (gettext) handling (bsc#1233612).
• CVE-2024-45777: integer overflow in gettext (bsc#1233613).
• CVE-2024-45778: bfs filesystem not fuzzing stable (bsc#1233606).
• CVE-2024-45779: bfs: heap overflow (bsc#1233608).
• CVE-2024-45780: overflow in tar/cpio (bsc#1233614).
• CVE-2024-45781: ufs: strcpy overflow (bsc#1233617).
• CVE-2024-45782: hfs: strcpy overflow (bsc#1233615).
• CVE-2024-45783: hfsplus: refcount overflow (bsc#1233616).
• CVE-2024-56737: heap-based buffer overflow in fs/hfs.c via crafted sblock data in an HFS filesystem (bsc#1234958).
• CVE-2025-0622: command/gpg: Use-after-free due to hooks not being removed on module unload (bsc#1236317).
• CVE-2025-0624: net: Out-of-bounds write in grub_net_search_config_file() (bsc#1236316).
• CVE-2025-0677: ufs: Integer overflow may lead to heap based out-of-bounds write when handling symlinks (bsc#1237002).
• CVE-2025-0678: squash4: Integer overflow may lead to heap based out-of-bounds write when reading data (bsc#1237006).
• CVE-2025-0684: reiserfs: Integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading data (bsc#1237008).
• CVE-2025-0685: jfs: Integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading data (bsc#1237009).
• CVE-2025-0686: romfs: Integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading data (bsc#1237010).
• CVE-2025-0689: udf: Heap based buffer overflow in grub_udf_read_block() may lead to arbitrary code execution (bsc#1237011).
• CVE-2025-0690: read: Integer overflow may lead to out-of-bounds write (bsc#1237012).
• CVE-2025-1118: commands/dump: The dump command is not in lockdown when secure boot is enabled (bsc#1237013).
• CVE-2025-1125: fs/hfs: Interger overflow may lead to heap based out-of-bounds write (bsc#1237014).

Other bugfixes:

• Bump upstream SBAT generation to 5

It was discovered that a specially crafted file system image could cause a heap-based out-of-bounds write. A local attacker could potentially use this to perform arbitrary code execution bypass and bypass secure boot protections. (CVE-2023-4692)

It was discovered that a specially crafted file system image could cause an out-of-bounds read. A physically-present attacker could possibly use this to leak sensitive information to the GRUB pager. (CVE-2023-4693)