CVE-2024-28940 is a high-severity heap-based buffer overflow vulnerability identified in the Microsoft OLE DB Driver for SQL Server, specifically affecting Microsoft SQL Server 2019 (GDR) version 15.0.0. This vulnerability is categorized under CWE-122, which involves improper handling of memory buffers leading to overflow conditions on the heap. The flaw allows an attacker to execute remote code by sending specially crafted requests to the vulnerable SQL Server instance via the OLE DB Driver interface. The vulnerability is remotely exploitable over the network (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R), such as convincing a user or application to initiate a connection or query that triggers the overflow. The impact is severe, affecting confidentiality, integrity, and availability (all rated high), enabling potential full system compromise. The vulnerability scope is unchanged (S:U), meaning exploitation affects only the vulnerable component and not other system components. Although no known exploits are currently reported in the wild, the presence of a heap overflow with remote code execution potential and no required privileges makes this a critical risk for organizations using the affected SQL Server version. The lack of a patch link indicates that a fix may not yet be publicly available or is pending release, increasing the urgency for mitigation. The vulnerability was reserved in March 2024 and published in April 2024, indicating recent discovery and disclosure.

For European organizations, the impact of CVE-2024-28940 is significant due to the widespread use of Microsoft SQL Server 2019 in enterprise environments, including finance, healthcare, government, and critical infrastructure sectors. Successful exploitation could lead to unauthorized data access, data corruption, or complete system takeover, compromising sensitive personal data protected under GDPR and other regulations. The ability to execute arbitrary code remotely without authentication increases the risk of ransomware deployment, espionage, or disruption of essential services. Given the high availability of SQL Server in European data centers and cloud environments, this vulnerability could affect multi-national corporations and public sector entities alike. The requirement for user interaction may limit automated exploitation but does not eliminate risk, especially in environments where automated processes or trusted applications interact with SQL Server instances. The absence of known exploits currently provides a window for proactive defense, but the high severity score and ease of exploitation necessitate immediate attention to prevent potential future attacks.

1. Immediate mitigation should include restricting network access to SQL Server instances using the OLE DB Driver to trusted hosts only, employing network segmentation and firewall rules to limit exposure. 2. Disable or restrict the use of the OLE DB Driver for SQL Server where possible, especially in environments where it is not required. 3. Monitor SQL Server logs and network traffic for unusual or unexpected queries that could indicate exploitation attempts. 4. Implement application-layer controls to validate and sanitize inputs that interact with SQL Server to reduce the risk of triggering the vulnerability. 5. Apply the official security patch from Microsoft as soon as it becomes available; in the meantime, consider deploying virtual patching via Web Application Firewalls (WAFs) or Intrusion Prevention Systems (IPS) with custom rules targeting exploit patterns. 6. Conduct thorough vulnerability scanning and penetration testing focused on SQL Server instances to identify exposure. 7. Educate users and administrators about the risk of social engineering or phishing that could trigger user interaction required for exploitation. 8. Maintain regular backups and incident response plans to quickly recover from potential compromise.