CVE-2025-0684
When performing a symlink lookup from a reiserfs filesystem, grub's reiserfs fs module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows.
Does this matter?
Lower severity and a low EPSS score (0.28%). Track it; it rarely justifies an emergency change on its own.
Description
A flaw was found in grub2. When performing a symlink lookup from a reiserfs filesystem, grub's reiserfs fs module uses user-controlled parameters from the filesystem geometry to determine the internal buffer size, however, it improperly checks for integer overflows. A maliciouly 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_reiserfs_read_symlink() will call grub_reiserfs_read_real() with a overflown length parameter, leading to a heap based out-of-bounds write during data reading. This flaw may be leveraged to corrupt grub's internal critical data and can result in arbitrary code execution, by-passing secure boot protections.
- CVSS 3.1
- 6.4 MEDIUMCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.28% probability · 20th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- gnu/grub2
- Source
- secalert@redhat.com
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.