Integer overflow in GNU Grub2
CVE-2025-0678
A flaw was found in grub2. When reading data from a squash4 filesystem, grub's squash4 fs 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 direct_read() will perform a heap based out-of-bounds write during data reading. This flaw may be leveraged to corrupt grub's internal critical data and may result in arbitrary code execution, by-passing secure boot protections.
Vulnerability class: Integer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.003 (19.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- access.redhat.com/security/cve/CVE-2025-0678 (vdb-entry, Broken Link)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Issue Tracking)
- lists.gnu.org/archive/html/grub-devel/2025-02/msg00024.html
Frequently asked questions
- What is CVE-2025-0678?
- CVE-2025-0678 is a high-severity vulnerability in GNU Grub2, classified under Integer Overflow or Wraparound. CVSS score: 7.8/10. Published 2025-03-03.
- How severe is CVE-2025-0678?
- High severity. CVSS v3 base score is 7.8 out of 10.
- Is CVE-2025-0678 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.