CVE-2024-35271 is a heap-based buffer overflow vulnerability classified under CWE-122, discovered in Microsoft SQL Server 2017 (GDR), specifically within the SQL Server Native Client OLE DB Provider component. This vulnerability allows remote code execution (RCE) when an attacker sends specially crafted requests to the vulnerable SQL Server instance. The flaw arises from improper handling of heap memory buffers, which can be overflowed to overwrite adjacent memory, enabling execution of arbitrary code with the privileges of the SQL Server process. The CVSS 3.1 base score is 8.8, indicating high severity, with attack vector being network (AV:N), no privileges required (PR:N), but user interaction is needed (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 exploits have been reported in the wild yet, the vulnerability poses a significant risk due to the widespread deployment of SQL Server 2017 in enterprise environments. The vulnerability was reserved in May 2024 and published in July 2024, with no patch links currently available, suggesting that organizations must monitor for updates closely. The vulnerability could be exploited by tricking a user into interacting with a malicious payload or connection attempt, potentially leading to full system compromise. The SQL Server Native Client OLE DB Provider is commonly used for database connectivity, increasing the attack surface for remote exploitation.

For European organizations, this vulnerability presents a critical risk to data confidentiality, integrity, and availability, especially in sectors relying heavily on Microsoft SQL Server 2017 for critical business applications and data storage. Exploitation could lead to unauthorized data access, data corruption, or complete service disruption. This could affect financial institutions, healthcare providers, government agencies, and large enterprises that depend on SQL Server for transactional and analytical workloads. The remote code execution capability means attackers could gain persistent footholds within networks, potentially moving laterally to compromise additional systems. The requirement for user interaction slightly reduces the risk but does not eliminate it, as social engineering or phishing could facilitate exploitation. The absence of known exploits in the wild currently provides a window for proactive defense, but the high severity and ease of network-based exploitation warrant urgent attention. Disruption of critical services could have cascading effects on European economies and public services.

Organizations should immediately inventory all instances of Microsoft SQL Server 2017 (GDR) and prioritize those exposed to untrusted networks. Until official patches are released, implement strict network segmentation and firewall rules to limit access to SQL Server ports (default 1433) only to trusted hosts and networks. Employ intrusion detection and prevention systems (IDS/IPS) with updated signatures to detect anomalous SQL Server traffic. Educate users about the risks of interacting with untrusted database connections or links to reduce the chance of user interaction exploitation. Monitor logs for unusual activity related to SQL Server Native Client OLE DB Provider connections. Prepare to deploy vendor patches promptly once available and test them in controlled environments before production rollout. Consider applying application-layer mitigations such as disabling or restricting the use of the Native Client OLE DB Provider if feasible. Regularly back up critical databases and verify recovery procedures to mitigate potential data loss from exploitation. Engage with Microsoft security advisories and threat intelligence feeds to stay informed about exploit developments.