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Fencer Vulns
medium 6.4

CVE-2025-0677 json

Grub2: ufs: integer overflow may lead to heap based out-of-bounds write when handling symlinks

published 2025-02-19 20 mo ago modified 2026-11-05 3 d ago also EUVD-2025-4654

cvss
6.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits
0
none known

Summary

A flaw was found in grub2. When performing a symlink lookup, the grub's UFS module checks the inode's data size to allocate the internal buffer to read the file content, however, it fails to check if the symlink data size has overflown. When this occurs, grub_malloc() may be called with a smaller value than needed. When further reading the data from the disk into the buffer, the grub_ufs_lookup_symlink() function will write past the end of the allocated size. An attack can leverage this by crafting a malicious filesystem, and as a result, it will corrupt data stored in the heap, allowing for arbitrary code execution used to by-pass secure boot mechanisms.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 1:2.12-15.el10_0
  • Red Hat Red Hat Enterprise Linux 9 1:2.06-104.el9_6
  • grub2 Debian 12 2.06-13+deb12u2
  • grub2 Debian 14, Debian 13 2.12-6

debian advisories DEBIAN-CVE-2025-0677

  • grub2 RHEL 10.0 1:2.12-15.el10_0
  • grub2-pc RHEL 10.0 1:2.12-15.el10_0
  • grub2-tools RHEL 10.0 1:2.12-15.el10_0
  • grub2-common RHEL 10.0 1:2.12-15.el10_0
  • grub2-efi-x64 RHEL 10.0 1:2.12-15.el10_0
  • grub2-ppc64le RHEL 10.0 1:2.12-15.el10_0
  • grub2-efi-aa64 RHEL 10.0 1:2.12-15.el10_0
  • grub2-tools-efi RHEL 10.0 1:2.12-15.el10_0

red hat advisories RHSA-2025:16154RHSA-2025:6990

  • grub2 Linux Micro 6.1 2.12-slfo.1.1_2.1
  • grub2 Linux Micro 6.0 2.12~rc1-6.1
  • grub2 SLE Micro 5.1 2.04-150300.3.11.1
  • grub2 SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Micro 5.2 +2 more 2.04-150300.22.52.3
  • grub2 SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +7 more 2.06-150400.11.55.2
  • grub2 SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 2.06-150500.29.43.2
  • grub2 SLE Module for Server Applications 15 SP6, SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 2.12-150600.8.18.2
  • grub2 SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 2.02-181.2

suse advisories SUSE-SU-2025:20863-1SUSE-SU-2025:20511-1SUSE-SU-2025:01961-1SUSE-SU-2025:0629-1SUSE-SU-2025:0607-1SUSE-SU-2025:0588-1

  • grub2 openSUSE Tumbleweed 2.12-35.1

opensuse advisories openSUSE-SU-2025:14822-1

  • grub2-common AlmaLinux 10 1:2.12-15.el10_0.alma.1
  • grub2-pc-modules AlmaLinux 10 1:2.12-15.el10_0.alma.1
  • grub2-efi-x64-modules AlmaLinux 10 1:2.12-15.el10_0.alma.1
  • grub2-ppc64le-modules AlmaLinux 10 1:2.12-15.el10_0.alma.1
  • grub2-efi-aa64-modules AlmaLinux 10 1:2.12-15.el10_0.alma.1
  • grub2-pc AlmaLinux 9 1:2.06-104.el9_6.alma.1
  • grub2-tools AlmaLinux 9 1:2.06-104.el9_6.alma.1
  • grub2-common AlmaLinux 9 1:2.06-104.el9_6.alma.1

almalinux advisories ALSA-2025:16154ALSA-2025:6990

  • grub2 Rocky Linux 9 1:2.06-104.el9_6
  • grub2 Rocky Linux 10 1:2.12-15.el10_0

rocky linux advisories RLSA-2025:6990RLSA-2025:16154

  • grub2 CBL-Mariner 2.0 2.06-15
  • grub2 Azure Linux 3.0 2.06-25

azure linux advisories AZL-56919AZL-57007

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-0677 updated cvss 6.4

grub2: UFS: Integer overflow may lead to heap based out-of-bounds write when handling symlinks

  • Red Hat Enterprise Linux 7 grub2, grub2-pc, grub2-efi, grub2-ppc64, grub2-tools, grub2-common, +15 more Red Hat Enterprise Linux 8 grub2, grub2-pc, grub2-tools, grub2-common, grub2-efi-x64, grub2-ppc64le, +13 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux BaseOS (v. 9) grub2 2.06-104.el9_6, grub2-pc 2.06-104.el9_6, grub2-tools 2.06-104.el9_6, grub2-common 2.06-104.el9_6, grub2-efi-x64 2.06-104.el9_6, grub2-ppc64le 2.06-104.el9_6, +10 more
    fixed: vendor fix RHSA-2025:6990
  • Red Hat Enterprise Linux BaseOS (v. 10) grub2 2.12-15.el10_0, grub2-pc 2.12-15.el10_0, grub2-tools 2.12-15.el10_0, grub2-common 2.12-15.el10_0, grub2-efi-x64 2.12-15.el10_0, grub2-ppc64le 2.12-15.el10_0, +10 more
    fixed: vendor fix RHSA-2025:16154

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
20 mo ago

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.4 CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat OpenShift Container Platform 4

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.