CVE-2025-0686

medium

Description

A flaw was found in grub2. When performing a symlink lookup from a romfs filesystem, grub's romfs filesystem module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciously crafted filesystem may lead some of those buffer size calculations to overflow, causing it to perform a grub_malloc() operation with a smaller size than expected. As a result, the grub_romfs_read_symlink() may cause out-of-bounds writes when the calling grub_disk_read() function. This issue may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution by-passing secure boot protections.

References

https://www.bleepingcomputer.com/news/security/microsoft-uses-ai-to-find-flaws-in-grub2-u-boot-barebox-bootloaders/

https://bugzilla.redhat.com/show_bug.cgi?id=2346121

https://access.redhat.com/security/cve/CVE-2025-0686

Details

Source: Mitre, NVD

Published: 2025-03-03

Updated: 2025-03-03

Risk Information

CVSS v2

Base Score: 5.9

Vector: CVSS2#AV:L/AC:H/Au:M/C:C/I:C/A:C

Severity: Medium

CVSS v3

Base Score: 6.4

Vector: CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Severity: Medium