Headline
Ubuntu Security Notice USN-6410-1
Ubuntu Security Notice 6410-1 - 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. 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.
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Ubuntu Security Notice USN-6410-1
October 04, 2023
grub2-signed, grub2-unsigned vulnerabilities
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 23.04
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
Summary:
Several security issues were fixed in GRUB2.
Software Description:
- grub2-signed: GRand Unified Bootloader
- grub2-unsigned: GRand Unified Bootloader
Details:
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)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 23.04:
grub-efi-amd64 2.06-2ubuntu17.2
grub-efi-amd64-bin 2.06-2ubuntu17.220:32
grub-efi-amd64-signed 1.193.2+2.06-2ubuntu17.2
grub-efi-arm64 2.06-2ubuntu17.2
grub-efi-arm64-bin 2.06-2ubuntu17.2
grub-efi-arm64-signed 1.193.2+2.06-2ubuntu17.2
Ubuntu 22.04 LTS:
grub-efi-amd64 2.06-2ubuntu14.4
grub-efi-amd64-bin 2.06-2ubuntu14.4
grub-efi-amd64-signed 1.187.6+2.06-2ubuntu14.4
grub-efi-arm64 2.06-2ubuntu14.4
grub-efi-arm64-bin 2.06-2ubuntu14.4
grub-efi-arm64-signed 1.187.6+2.06-2ubuntu14.4
Ubuntu 20.04 LTS:
grub-efi-amd64-signed 1.187.6~20.04.1+2.06-2ubuntu14.4
grub-efi-arm64-signed 1.187.6~20.04.1+2.06-2ubuntu14.4
In general, a standard system update will make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-6410-1
CVE-2023-4692, CVE-2023-4693
Package Information:
https://launchpad.net/ubuntu/+source/grub2-signed/1.193.2
https://launchpad.net/ubuntu/+source/grub2-unsigned/2.06-2ubuntu17.2
https://launchpad.net/ubuntu/+source/grub2-signed/1.187.6
https://launchpad.net/ubuntu/+source/grub2-unsigned/2.06-2ubuntu14.4
https://launchpad.net/ubuntu/+source/grub2-signed/1.187.6~20.04.1
Related news
Red Hat Security Advisory 2024-2456-03 - An update for grub2 is now available for Red Hat Enterprise Linux 9. Issues addressed include code execution, out of bounds read, and out of bounds write vulnerabilities.
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Gentoo Linux Security Advisory 202311-14 - Multiple vulnerabilities have been discovered in GRUB, which may lead to secure boot circumvention or code execution. Versions greater than or equal to 2.06-r9 are affected.
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.
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.
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