CVE-2023-36402 is a heap-based buffer overflow vulnerability identified in the Microsoft Windows Defender Application Control (WDAC) OLE DB provider component for SQL Server on Windows 10 Version 1809 (build 10.0.17763.0). The vulnerability arises from improper handling of input data leading to a heap overflow condition, which can be exploited remotely by an unauthenticated attacker. The attack vector is network-based (AV:N), requiring no privileges (PR:N) but does require user interaction (UI:R), such as opening a malicious file or link. Exploiting this vulnerability allows an attacker to execute arbitrary code in the context of the affected application, potentially leading to full system compromise including confidentiality, integrity, and availability impacts. The CVSS v3.1 base score is 8.8, reflecting high severity due to its remote exploitability and critical impact. Although no public exploits are currently known, the vulnerability is considered serious given the widespread use of Windows 10 and SQL Server in enterprise environments. The vulnerability was reserved in June 2023 and published in November 2023, with no official patches listed yet, indicating organizations should monitor for updates and consider interim mitigations.

For European organizations, this vulnerability poses a significant risk especially for those still operating legacy Windows 10 Version 1809 systems integrated with SQL Server environments. Exploitation could lead to remote code execution, enabling attackers to gain unauthorized access, steal sensitive data, disrupt operations, or deploy ransomware. Critical infrastructure, financial institutions, healthcare providers, and government agencies using affected systems could face severe operational and reputational damage. The requirement for user interaction slightly reduces the risk but does not eliminate it, as phishing or social engineering could facilitate exploitation. The lack of known exploits in the wild provides a window for proactive defense, but the high CVSS score and potential impact necessitate urgent attention. Organizations relying on Windows 10 1809 should assess their exposure and prioritize remediation to avoid potential breaches.

Organizations should immediately inventory their Windows 10 systems to identify those running Version 1809 (build 10.0.17763.0) and assess the presence of the WDAC OLE DB provider for SQL Server. Since no official patches are currently listed, organizations should monitor Microsoft security advisories closely for forthcoming updates. In the interim, applying any available workarounds or disabling the vulnerable component if feasible can reduce risk. Enhancing endpoint protection, enforcing strict user awareness training to prevent social engineering, and implementing network segmentation to limit exposure of vulnerable systems are recommended. Additionally, organizations should consider upgrading affected systems to supported Windows versions with active security updates. Regular vulnerability scanning and penetration testing focusing on this vector can help detect potential exploitation attempts early.