#VU95182 Incorrect default permissions in efi-shell-x64 (Ubuntu package) - CVE-2023-48733

Vulnerability identifier: #VU95182

Vulnerability risk: Low

CVSSv4.0: 4 [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/E:U/U:Clear]

CVE-ID: CVE-2023-48733

CWE-ID: CWE-276

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
efi-shell-x64 (Ubuntu package)
Operating systems & Components / Operating system package or component

Vendor: Canonical Ltd.

Description

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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

efi-shell-x64 (Ubuntu package): before 2023.05-2ubuntu0.1

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External links
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

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Q & A

Can this vulnerability be exploited remotely?

No. The attacker should have physical access to the system in order to successfully exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.