CVE-2025-0684

CVE-2025-0684 is a heap-based out-of-bounds write vulnerability in GNU GRUB2, specifically within its reiserfs filesystem module. This flaw allows an attacker to craft a malicious reiserfs filesystem that causes integer overflows during buffer size calculations, leading to a smaller-than-expected memory allocation. Consequently, a subsequent read operation can result in an out-of-bounds write, corrupting GRUB's critical data and potentially enabling arbitrary code execution, even bypassing Secure Boot. The vulnerability has a CVSS score of 6.4 (Medium), indicating a local attack vector with high attack complexity, requiring high privileges, but with no user interaction. Its potential impact includes high confidentiality, integrity, and availability compromise. Currently, there is no evidence of active exploitation, and no public exploit code (Metasploit, Nuclei, ExploitDB) is available. While community discussion is limited, the vulnerability has garnered some media attention, including an article from BleepingComputer.