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.
Advisories
Source ID Title
EUVD EUVD EUVD-2025-5576 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.
Fixes

Solution

No solution given by the vendor.


Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

History

Mon, 28 Jul 2025 17:30:00 +0000

Type Values Removed Values Added
First Time appeared Gnu
Gnu grub2
CPEs cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:*
Vendors & Products Gnu
Gnu grub2

Sat, 05 Jul 2025 06:00:00 +0000

Type Values Removed Values Added
CPEs cpe:/o:redhat:enterprise_linux:10

Tue, 04 Mar 2025 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 03 Mar 2025 17:30:00 +0000

Type Values Removed Values Added
Title grub2: romfs: Integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading dat Grub2: romfs: integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading dat
First Time appeared Redhat
Redhat enterprise Linux
Redhat openshift
CPEs cpe:/a:redhat:openshift:4
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat openshift
References

Thu, 20 Feb 2025 02:45:00 +0000

Type Values Removed Values Added
Description No description is available for this CVE. 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.

Wed, 19 Feb 2025 14:00:00 +0000

Type Values Removed Values Added
Description No description is available for this CVE.
Title grub2: romfs: Integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading dat
Weaknesses CWE-787
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.4, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2025-07-28T17:35:05.229Z

Reserved: 2025-01-23T19:13:28.900Z

Link: CVE-2025-0686

cve-icon Vulnrichment

Updated: 2025-03-04T16:11:59.740Z

cve-icon NVD

Status : Analyzed

Published: 2025-03-03T18:15:30.930

Modified: 2025-07-28T17:23:26.000

Link: CVE-2025-0686

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-02-18T18:00:00Z

Links: CVE-2025-0686 - Bugzilla

cve-icon OpenCVE Enrichment

No data.