CVE-2023-21933 in MySQL Server
Summary
by MITRE • 04/18/2023
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: DDL). Supported versions that are affected are 8.0.32 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).
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 05/08/2025
The vulnerability identified as CVE-2023-21933 represents a significant availability risk within Oracle MySQL Server version 8.0.32 and earlier releases. This flaw resides within the Server: DDL component, which governs data definition language operations including table creation, modification, and deletion processes. The vulnerability's classification as easily exploitable indicates that attackers with high privileges and network access can leverage this weakness to disrupt MySQL server operations. The attack vector permits exploitation through multiple network protocols, making the vulnerability particularly concerning for environments where MySQL services are exposed to external networks or where privilege escalation has occurred within the system.
The technical nature of this vulnerability manifests as a complete denial of service condition that can cause MySQL Server to hang or repeatedly crash. This type of flaw typically arises from improper handling of specific DDL operations that may not adequately validate input parameters or manage memory allocation during complex database schema modifications. The vulnerability's impact extends beyond simple service interruption, as the repeated crash scenario suggests a potential for sustained disruption that could severely impact database availability and business continuity. From a cybersecurity perspective, this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, though the specific implementation may involve other memory corruption patterns related to DDL processing.
The operational impact of CVE-2023-21933 presents substantial risk to organizations relying on MySQL for critical database operations. A successful exploitation can result in complete service unavailability, requiring manual intervention to restore database functionality. This disruption affects not only database operations but can also impact applications and services that depend on MySQL for data persistence and transaction management. The CVSS 3.1 score of 4.9 indicates a medium severity vulnerability, yet the availability impact rating of high (A:H) underscores the critical nature of the disruption potential. Organizations with high availability requirements or those operating in regulated environments where database uptime is mandated face particular risk from this vulnerability, as the complete DOS condition can lead to compliance violations and service level agreement breaches.
Mitigation strategies for CVE-2023-21933 should prioritize immediate patching of affected MySQL Server instances to version 8.0.33 or later, which contains the necessary fixes for this vulnerability. Network segmentation and access controls should be implemented to limit exposure of MySQL services to only trusted networks and authorized users, reducing the attack surface available to potential exploiters. Monitoring systems should be enhanced to detect unusual patterns in database server behavior or repeated connection failures that might indicate exploitation attempts. Security teams should also consider implementing database activity monitoring solutions that can identify and alert on potentially malicious DDL operations. According to ATT&CK framework, this vulnerability maps to techniques involving privilege escalation and service disruption, making it relevant to both initial access and persistence phases of cyber operations. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in database configurations and ensure that all systems maintain current security postures against evolving threats.