Incorrect default permissions in efi-shell-x64 (Ubuntu package) - CVE-2023-48733

Vulnerability identifier: #VU95182

CSH Severity: Low

CVSS v4: 7 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2023-48733

CWE-ID: CWE-276

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to incorrect default permissions on the UEFI Shell. A local user can bypass the Secure Boot and escalate privileges on the system.

efi-shell-x64 (Ubuntu package)
ovmf (Ubuntu package)
qemu-efi-aarch64 (Ubuntu package)
qemu-efi-arm (Ubuntu package)
qemu-efi (Ubuntu package)
edk2 (Debian package)
efi-shell-aa64 (Ubuntu package)
efi-shell-arm (Ubuntu package)
Debian Linux
Ubuntu

Install updates from vendor's website.

efi-shell-x64 (Ubuntu package) - update to 2023.05-2ubuntu0.1
ovmf (Ubuntu package) - addressed in versions 0~20191122.bd85bf54-2ubuntu3.5, 2022.02-3ubuntu0.22.04.2, 2023.05-2ubuntu0.1
qemu-efi-aarch64 (Ubuntu package) - addressed in versions 0~20191122.bd85bf54-2ubuntu3.5, 2022.02-3ubuntu0.22.04.2, 2023.05-2ubuntu0.1
qemu-efi-arm (Ubuntu package) - addressed in versions 0~20191122.bd85bf54-2ubuntu3.5, 2022.02-3ubuntu0.22.04.2, 2023.05-2ubuntu0.1
qemu-efi (Ubuntu package) - addressed in versions 0~20191122.bd85bf54-2ubuntu3.5, 2022.02-3ubuntu0.22.04.2
edk2 (Debian package) - addressed in versions 2020.11-2+deb11u2, 2022.11-6+deb12u1
efi-shell-aa64 (Ubuntu package) - update to 2023.05-2ubuntu0.1
efi-shell-arm (Ubuntu package) - update to 2023.05-2ubuntu0.1

• https://bugs.launchpad.net/ubuntu/+source/edk2/+bug/2040137
• https://nvd.nist.gov/vuln/detail/CVE-2023-48733
• https://www.openwall.com/lists/oss-security/2024/02/14/4
• https://bugs.launchpad.net/ubuntu/+source/lxd/+bug/2040139
• https://lists.debian.org/debian-lts-announce/2024/06/msg00028.html

• Debian update for edk2
• Ubuntu update for edk2