CVE-2025-21180 is a heap-based buffer overflow vulnerability classified under CWE-122, found in the exFAT file system driver of Microsoft Windows 10 Version 1507 (build 10.0.10240.0). The vulnerability arises from improper handling of data structures in the exFAT driver, which can lead to memory corruption when processing specially crafted exFAT file system metadata or files. An attacker with local access and the ability to induce user interaction (such as inserting a malicious exFAT-formatted USB drive or opening a crafted file) can trigger this overflow, resulting in arbitrary code execution under the context of the affected user. The flaw impacts confidentiality, integrity, and availability by potentially allowing execution of malicious payloads, privilege escalation, or system compromise. The CVSS v3.1 score of 7.8 reflects the high severity due to low attack complexity, no privileges required, but requiring user interaction and local access. No public exploits have been reported yet, but the vulnerability is significant given the widespread use of exFAT for removable media and the presence of legacy Windows 10 installations in enterprise environments. The lack of available patches for this specific version highlights the importance of upgrading to supported Windows releases. The vulnerability was reserved in December 2024 and published in March 2025, indicating recent discovery and disclosure.

For European organizations, this vulnerability poses a significant risk especially to those still operating legacy Windows 10 Version 1507 systems, which may be found in industrial control systems, embedded devices, or legacy enterprise environments. Exploitation could lead to local code execution, enabling attackers to install malware, steal sensitive data, or disrupt operations. The use of exFAT-formatted removable media is common in many sectors, increasing the attack surface. Critical infrastructure sectors such as manufacturing, energy, and transportation that rely on legacy Windows systems are particularly vulnerable. The confidentiality of sensitive information could be compromised, integrity of systems altered, and availability impacted through system crashes or persistent malware. Although remote exploitation is not possible, insider threats or social engineering attacks that induce user interaction could trigger the vulnerability. The absence of known exploits in the wild provides a window for mitigation, but the risk remains high due to the potential impact and ease of local exploitation.

1. Upgrade all affected Windows 10 Version 1507 systems to the latest supported Windows 10 or Windows 11 versions where this vulnerability is patched. 2. Implement strict device control policies to restrict or monitor the use of exFAT-formatted removable media, especially from untrusted sources. 3. Educate users about the risks of inserting unknown USB drives or opening files from untrusted origins to reduce the likelihood of triggering the vulnerability. 4. Employ endpoint detection and response (EDR) solutions to monitor for suspicious activity related to file system access or code execution attempts. 5. Where upgrading is not immediately feasible, consider disabling exFAT support if possible or isolating legacy systems from critical networks to limit exposure. 6. Maintain up-to-date backups and incident response plans to quickly recover from potential exploitation. 7. Monitor threat intelligence sources for any emerging exploits targeting this vulnerability to enable rapid response.