CVE-2025-61661
MediumCVSS 4.8Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
A vulnerability has been identified in the GRUB (Grand Unified Bootloader) component due to improper string conversion when reading data from a USB device. A local attacker can connect a maliciously configured USB device during boot sequence, causing GRUB to crash and leading to a Denial of Service (DoS). Data corruption may also be possible, but due to exploit complexity the impact is likely limited.
Risk Assessment
The risk for the organization is the possibility of a DoS attack during the boot process, which can prevent servers or workstations from starting. The attack requires physical access to the device, limiting the threat mainly to environments with uncontrolled USB port access.
Recommendation
It is recommended to immediately apply security patches provided by the GRUB distributor and restrict physical access to USB ports on critical systems. Consider disabling USB booting in BIOS/UEFI settings if not required.
Original NVD description (English source)
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.