CVE-2024-35271 is a high-severity heap-based buffer overflow vulnerability (CWE-122) identified in Microsoft SQL Server 2017 (GDR), specifically affecting version 14.0.0. The vulnerability resides within the SQL Server Native Client OLE DB Provider component, which is responsible for database connectivity and data access. This flaw allows an unauthenticated remote attacker to execute arbitrary code on the affected system by sending a specially crafted request that triggers the buffer overflow condition. The vulnerability has a CVSS 3.1 base score of 8.8, indicating a high impact with network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is unchanged (S:U), and the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). Although no known exploits are currently reported in the wild, the vulnerability's characteristics make it a significant risk, especially in environments where SQL Server 2017 is exposed to untrusted networks or users. The lack of a published patch link suggests that mitigation may currently rely on workarounds or awaiting official updates from Microsoft. The vulnerability was reserved in May 2024 and published in July 2024, indicating recent discovery and disclosure. Given the critical role of SQL Server in enterprise data management, successful exploitation could lead to full system compromise, data theft, or disruption of services.

For European organizations, this vulnerability poses a substantial risk due to the widespread use of Microsoft SQL Server 2017 in enterprise environments for critical data storage and business applications. Exploitation could lead to unauthorized remote code execution, allowing attackers to gain control over database servers, potentially leading to data breaches involving sensitive personal data protected under GDPR, disruption of business operations, and damage to organizational reputation. The high impact on confidentiality, integrity, and availability means that attackers could exfiltrate or manipulate data, deploy ransomware, or use compromised servers as pivot points for further network infiltration. Organizations in sectors such as finance, healthcare, government, and critical infrastructure are particularly vulnerable due to the sensitivity of their data and regulatory requirements. The requirement for user interaction slightly reduces the risk but does not eliminate it, as phishing or social engineering could be used to trigger the exploit. The absence of known exploits in the wild provides a window for proactive defense, but the high severity score necessitates urgent attention.

European organizations should immediately assess their exposure to Microsoft SQL Server 2017 (version 14.0.0) instances, especially those accessible from untrusted networks. Specific mitigation steps include: 1) Implement network segmentation and firewall rules to restrict access to SQL Server instances only to trusted hosts and networks, minimizing exposure to potential attackers. 2) Employ application-layer gateways or proxy solutions that can inspect and filter SQL Server traffic to detect anomalous or malformed requests that might trigger the overflow. 3) Enforce strict user interaction policies and awareness training to reduce the risk of social engineering attacks that could facilitate exploitation. 4) Monitor logs and network traffic for unusual activity related to SQL Server Native Client OLE DB Provider communications. 5) Apply any available Microsoft security updates or patches as soon as they are released; if patches are not yet available, consider temporary disabling or restricting the vulnerable component where feasible. 6) Use intrusion detection and prevention systems (IDS/IPS) with updated signatures to detect attempts to exploit this vulnerability. 7) Conduct thorough vulnerability scans and penetration tests focusing on SQL Server environments to identify and remediate exposure. 8) Prepare incident response plans specifically addressing potential SQL Server compromises to enable rapid containment and recovery.