CVE-2024-21177 is a vulnerability identified in Oracle's MySQL NDB Cluster, specifically within the Server Optimizer component. It affects all versions up to 8.0.37 and 8.4.0 and prior. The flaw allows an attacker with low privileges and network access through multiple protocols to trigger a denial-of-service condition by causing the MySQL Cluster to hang or crash repeatedly. The vulnerability is classified under CWE-400, indicating a resource exhaustion or DoS issue. The CVSS 3.1 base score is 6.5, reflecting a medium severity primarily due to its impact on availability (A:H) without affecting confidentiality or integrity. The attack vector is network-based (AV:N), requires low attack complexity (AC:L), and only low privileges (PR:L), with no user interaction (UI:N) needed. The scope remains unchanged (S:U), meaning the impact is confined to the vulnerable component. Although no exploits have been observed in the wild, the vulnerability's characteristics suggest it could be weaponized to disrupt database services, potentially affecting applications and services dependent on MySQL Cluster for high availability and fault tolerance. The absence of patches at the time of reporting necessitates immediate attention to mitigation strategies to prevent exploitation.

The primary impact of CVE-2024-21177 is on the availability of MySQL NDB Cluster services. Successful exploitation can cause the database cluster to hang or crash repeatedly, resulting in a complete denial-of-service. For European organizations, especially those in sectors such as finance, telecommunications, manufacturing, and critical infrastructure that rely on MySQL Cluster for distributed, high-availability database solutions, this can lead to significant operational disruptions. Service outages may affect transaction processing, data availability, and business continuity. Additionally, organizations providing cloud or managed database services using MySQL NDB Cluster could face reputational damage and SLA breaches. Since the vulnerability requires only low privileges and network access, internal threat actors or compromised low-privilege accounts could exploit it, increasing the risk profile. The lack of impact on confidentiality and integrity reduces risks of data breaches or data manipulation but does not mitigate the operational risks posed by service unavailability.

1. Monitor Oracle's official channels for the release of security patches addressing CVE-2024-21177 and apply them promptly once available. 2. Restrict network access to MySQL NDB Cluster nodes by implementing strict firewall rules and network segmentation, limiting exposure to trusted hosts and management networks only. 3. Employ network-level intrusion detection and prevention systems (IDS/IPS) to detect anomalous traffic patterns indicative of exploitation attempts targeting MySQL protocols. 4. Enforce the principle of least privilege for database users and services to minimize the risk posed by low-privileged attackers. 5. Regularly audit and monitor MySQL Cluster logs and system performance metrics to detect early signs of hangs or crashes. 6. Consider implementing redundancy and failover mechanisms outside of MySQL Cluster to maintain service continuity during potential DoS events. 7. Educate internal teams about this vulnerability to ensure rapid incident response if exploitation is suspected. 8. Evaluate the use of network-level authentication and encryption protocols to reduce the attack surface exposed via multiple protocols.