CVE-2024-21361 is a high-severity heap-based buffer overflow vulnerability (CWE-122) affecting Microsoft Windows 10 Version 1809, specifically within the Windows Defender Application Control (WDAC) OLE DB provider for SQL Server. This vulnerability allows remote code execution (RCE) without requiring privileges or authentication, but does require user interaction. The flaw arises from improper handling of memory buffers in the OLE DB provider component, which can be exploited by an attacker to execute arbitrary code in the context of the affected system. The CVSS v3.1 base score is 8.8, reflecting the critical impact on confidentiality, integrity, and availability, with an attack vector over the network and low attack complexity. The vulnerability affects Windows 10 build 17763.0, which corresponds to Version 1809, a version that, while superseded by newer releases, remains in use in some enterprise environments. No known exploits are currently reported in the wild, and no official patches have been linked yet, indicating that organizations should prioritize mitigation and monitoring. The vulnerability's exploitation requires user interaction, such as opening a malicious file or connection, but does not require privileges, making it a significant risk especially in environments where legacy Windows 10 1809 systems are still operational and connected to SQL Server environments leveraging WDAC OLE DB provider functionality.

For European organizations, this vulnerability poses a substantial risk, particularly for enterprises and public sector entities still running Windows 10 Version 1809 in their infrastructure. The ability to achieve remote code execution with high impact on confidentiality, integrity, and availability means attackers could potentially gain full control over affected systems, leading to data breaches, disruption of critical services, or lateral movement within networks. Organizations using SQL Server with WDAC OLE DB provider components are at heightened risk. Given the widespread use of Windows 10 in Europe, especially in government, finance, healthcare, and manufacturing sectors, exploitation could result in significant operational disruption and data compromise. The lack of known exploits in the wild currently provides a window for proactive defense, but the high severity score and ease of remote exploitation without privileges make timely mitigation critical to prevent potential targeted attacks or future exploit development.

European organizations should immediately identify and inventory all systems running Windows 10 Version 1809, focusing on those utilizing SQL Server with WDAC OLE DB provider components. Although no official patch links are available yet, organizations should monitor Microsoft security advisories closely for updates and apply patches promptly once released. In the interim, implement network-level controls to restrict access to SQL Server instances and limit exposure to untrusted networks. Employ application whitelisting and endpoint protection solutions capable of detecting anomalous behavior related to OLE DB provider usage. Educate users about the risks of interacting with unsolicited files or links to reduce the likelihood of user interaction exploitation. Additionally, enable and review detailed logging and monitoring for unusual activities on affected systems to detect potential exploitation attempts early. Consider upgrading affected systems to supported Windows versions where this vulnerability is not present or has been patched, to reduce the attack surface.