CVE-2025-0689: gnu grub2 Classic Buffer Overflow

Vulnerability summary

CVE-2025-0689 is a high (CVSS 7.8) Classic Buffer Overflow vulnerability in gnu grub2. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40% of scored vulnerabilities.

Timeline

1. 03-03-2025
   PublishedVulnerability first disclosed.
2. 29-06-2026
   Last modifiedVulnerability information updated.

Description

When reading data from disk, the grub's UDF filesystem module utilizes the user controlled data length metadata to allocate its internal buffers. In certain scenarios, while iterating through disk sectors, it assumes the read size from the disk is always smaller than the allocated buffer size which is not guaranteed. A crafted filesystem image may lead to a heap-based buffer overflow resulting in critical data to be corrupted, resulting in the risk of arbitrary code execution by-passing secure boot protections.

• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.