Overview
CVE-2025-61662 is a medium-severity Use-After-Free vulnerability affecting the gettext module in GRUB (GRand Unified Bootloader). This flaw can be exploited to cause a denial-of-service (DoS) condition. The vulnerability was published on 2025-11-18T19:15:50.203.
Technical Details
The core of this vulnerability lies in a programming error within GRUB’s gettext module. Specifically, the gettext command remains registered in memory even after the module containing it is unloaded. If an attacker can subsequently invoke this orphaned command, the application attempts to access a memory location that is no longer valid, leading to a Use-After-Free condition. This memory corruption can cause GRUB to crash.
CVSS Analysis
- Severity: MEDIUM
- CVSS Score: 4.9
A CVSS score of 4.9 indicates a medium severity. While a successful exploit is possible, the impact is primarily limited to a denial-of-service. Possible data integrity or confidentiality compromise is not discarded.
Possible Impact
Exploiting CVE-2025-61662 can result in:
- Denial of Service (DoS): A crash of the GRUB bootloader, preventing the system from booting. This could disrupt critical systems and require manual intervention to recover.
- Possible Data Compromise: It is possible that an attacker could leverage the use-after-free to manipulate memory in a way that allows access to or alteration of data used by the bootloader or early kernel, although the liklihood of this is low.
Mitigation or Patch Steps
The recommended mitigation is to apply the patch provided by the GRUB developers or upgrade to a version of GRUB that includes the fix. Check your Linux distribution’s security advisories for updates and instructions. Contact your distribution vendor for details.
Steps to apply a patch or upgrade:
- Monitor your distribution’s security announcements.
- Apply the patch or upgrade the GRUB package as soon as it becomes available.
- Reboot the system after applying the patch or upgrade to ensure the changes are applied.
