CVE-2025-0684 Grub2: reiserfs: integer overflow when handling symlinks may lead to heap based out-of-bounds write when reading data

Medium 6.4 Published Updated

A malicious ReiserFS filesystem can trigger an integer overflow in GRUB2, leading to heap corruption and arbitrary code execution that bypasses Secure Boot.

Exploited in the wild
Not known
Login needed
An administrator
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2025-0684?

CVE-2025-0684 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 3 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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.

Weakness: CWE-787

Which versions are affected by CVE-2025-0684?

It affects 1 product.

Products include Gnu Grub2.

How do I fix CVE-2025-0684?

Apply the vendor's patch.

Is CVE-2025-0684 being exploited?

There is no known exploitation of CVE-2025-0684 in the wild and no public exploit code.

Sources

Also known as AZL-57678, AZL-57707, BELL-CVE-2025-0684, DEBIAN-CVE-2025-0684, GHSA-mf4f-2vjv-3rq6, UBUNTU-CVE-2025-0684.

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