CVE-2025-61661 Grub2: grub2: out-of-bounds write via malicious usb device

Description

A vulnerability has been identified in the GRUB (Grand Unified Bootloader) component. This flaw occurs because the bootloader mishandles string conversion when reading information from a USB device, allowing an attacker to exploit inconsistent length values. A local attacker can connect a maliciously configured USB device during the boot sequence to trigger this issue. A successful exploitation may lead GRUB to crash, leading to a Denial of Service. Data corruption may be also possible, although given the complexity of the exploit the impact is most likely limited.

Exploitable with physical access to the machine, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector

Physical

Attack complexity

High

Privileges required

None

Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

High

Affected products and versions