CVE-2024-21130 is a vulnerability identified in the Oracle MySQL Server product, specifically within the Server Optimizer component. It affects all versions up to 8.0.37 and 8.4.0 and prior. The vulnerability allows an attacker with high privileges and network access via multiple protocols to cause a denial of service (DoS) condition by triggering a hang or repeated crash of the MySQL Server. The attack vector is network-based with low attack complexity, requiring no user interaction but necessitating high privileges, which implies the attacker must already have significant access to the system or network. The vulnerability impacts availability only, with no confidentiality or integrity compromise. The CVSS 3.1 score of 4.9 reflects a medium severity primarily due to the potential for service disruption. The underlying weakness corresponds to CWE-400, indicating a resource exhaustion or DoS condition. No public exploits have been reported yet, but the ease of causing a DoS with network access and high privileges makes it a concern for environments where MySQL uptime is critical. The lack of patch links suggests that organizations should monitor Oracle advisories closely for updates. The vulnerability affects multiple protocols, increasing the attack surface if MySQL is exposed externally or internally to untrusted networks.

For European organizations, the primary impact of CVE-2024-21130 is the potential for denial of service against MySQL Server instances. This can disrupt business-critical applications relying on MySQL databases, including web services, ERP systems, and data analytics platforms. Availability loss can lead to operational downtime, financial losses, and reputational damage, especially for sectors such as finance, healthcare, telecommunications, and government services that depend heavily on database availability. Since exploitation requires high privileges, the threat is more relevant in environments where attackers have already gained elevated access, such as through insider threats or post-compromise lateral movement. The multi-protocol exposure increases risk in complex network environments. European organizations with MySQL servers exposed to internal or external networks without strict access controls are particularly vulnerable. The absence of confidentiality or integrity impact reduces the risk of data breaches but does not diminish the operational risk posed by service outages.

1. Apply patches from Oracle immediately once they become available for affected MySQL versions to remediate the vulnerability. 2. Restrict network access to MySQL servers by implementing strict firewall rules and network segmentation, allowing only trusted hosts and services to connect. 3. Limit the number of users with high privileges on MySQL servers and enforce the principle of least privilege to reduce the risk of exploitation. 4. Monitor MySQL server logs and system performance metrics for signs of hangs, crashes, or unusual resource consumption that could indicate exploitation attempts. 5. Employ intrusion detection and prevention systems (IDS/IPS) to detect anomalous network activity targeting MySQL protocols. 6. Consider deploying MySQL in high-availability configurations with failover capabilities to minimize downtime in case of a DoS event. 7. Conduct regular security audits and penetration testing to identify and remediate privilege escalation paths that could enable attackers to gain the required high privileges. 8. Educate system administrators and security teams about this vulnerability and ensure incident response plans include scenarios involving MySQL service disruptions.