CVE-2024-21135 in MySQL Server
Summary
by MITRE • 07/17/2024
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.36 and prior and 8.3.0 and prior. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 10/24/2024
The vulnerability identified as CVE-2024-21135 represents a critical availability issue within Oracle MySQL Server's optimizer component, affecting versions 8.0.36 and earlier, as well as 8.3.0 and prior releases. This flaw exists within the server's query optimization logic where specific malformed queries can trigger unexpected behavior in the database engine's execution path. The vulnerability's classification as easily exploitable indicates that attackers with high privileges and network access can leverage this weakness through multiple communication protocols to target MySQL instances. The attack surface is particularly concerning because it allows for complete denial of service conditions where the targeted MySQL server becomes unresponsive or enters a continuous crash loop, effectively rendering database services unavailable to legitimate users and applications.
The technical nature of this vulnerability stems from improper handling of certain query optimization scenarios within the MySQL Server's internal execution engine. When specific complex queries are processed through the optimizer component, the system fails to properly validate or handle edge cases in the query execution plan generation, leading to memory corruption or execution path failures. This flaw operates at a fundamental level within the database server's operational logic, where the optimizer component is responsible for determining the most efficient execution strategy for SQL queries. The vulnerability's impact is amplified by its ability to cause complete system hangs or repeated crashes, making it particularly dangerous in production environments where database availability is critical. According to CVSS 3.1 scoring methodology, the vulnerability receives a base score of 4.9 with a high availability impact, reflecting the severe consequences of successful exploitation. The attack vector requires network access with high privileges, indicating that the vulnerability is not easily exploitable by casual attackers but poses significant risk to organizations where privileged access may be compromised.
The operational impact of CVE-2024-21135 extends beyond simple service disruption to encompass potential business continuity issues and data availability concerns for organizations relying on MySQL databases. When exploited successfully, this vulnerability can cause complete database server outages that may last for extended periods, requiring manual intervention to restore service. The repeated crash scenario creates additional operational burden for system administrators who must monitor and recover from frequent service interruptions. Organizations using MySQL in mission-critical applications face significant risk of data access disruption, application downtime, and potential financial losses due to service unavailability. The vulnerability's presence in multiple version streams including both the 8.0 and 8.3 release lines means that a broad range of MySQL installations may be affected, requiring widespread patch management efforts across database deployments. This type of vulnerability aligns with CWE-121, which addresses buffer overflow conditions, and represents a clear violation of the principle of least privilege since it requires only high-privilege access rather than administrative credentials.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected MySQL installations to the latest supported versions that contain the necessary security fixes. Organizations should implement network segmentation and access controls to limit exposure of MySQL servers to only authorized network segments and users with legitimate business requirements. Monitoring and alerting systems should be enhanced to detect unusual patterns of database server crashes or performance degradation that may indicate exploitation attempts. Network-level controls such as firewalls and intrusion detection systems can help limit the attack surface by restricting access to MySQL ports and protocols to trusted sources only. Additionally, database administrators should conduct thorough vulnerability assessments to identify and remediate any other potential weaknesses in their MySQL deployment configurations. The remediation approach should also include implementing proper backup and recovery procedures to minimize downtime impact during the patching process. Organizations should consider implementing database activity monitoring solutions that can detect and alert on anomalous query patterns that might indicate exploitation attempts targeting this specific vulnerability. The ATT&CK framework classification for this vulnerability would likely map to T1499.004, which addresses network denial of service attacks, and potentially T1566.001 for initial access through network-based exploitation techniques.