CVE-2023-21919 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).
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Analysis
by VulDB Data Team • 05/08/2025
The vulnerability identified as CVE-2023-21919 represents a significant availability risk within Oracle MySQL Server versions 8.0.32 and earlier, specifically affecting the Server: DDL component. This weakness manifests as a flaw in the database server's handling of Data Definition Language operations, which form the foundation of database schema management and structural modifications. The vulnerability's classification as easily exploitable indicates that sophisticated attack techniques are not required, making it particularly dangerous in environments where network access is available to potential adversaries. The attack vector requires high privileged access, suggesting that the vulnerability targets authenticated users who possess sufficient permissions to interact with the database server through multiple network protocols.
The technical nature of this vulnerability stems from improper handling of certain DDL operations within the MySQL Server's architecture, creating conditions where maliciously crafted database schema modifications can trigger system instability. When exploited, the vulnerability enables attackers to cause complete denial of service conditions by inducing hangs or frequent crashes in the MySQL Server process. This behavior aligns with the availability impact classification, where the system becomes unusable to legitimate users while maintaining the potential for recovery through system restarts or process termination. The CVSS 3.1 scoring of 4.9 reflects the moderate severity of the availability impact, considering that the vulnerability requires high privileges but can cause complete system unavailability. The attack requires network access from a position that allows the attacker to send malicious DDL commands to the server, typically through standard database connection protocols.
The operational impact of this vulnerability extends beyond simple service disruption, as database servers form the backbone of numerous enterprise applications and data management systems. When a MySQL Server experiences frequent crashes or hangs due to this vulnerability, it can cascade into broader system failures affecting applications that depend on database availability, potentially leading to extended downtime and data access interruptions. Organizations utilizing affected MySQL versions face significant risk, particularly in environments where database administrators or other high-privileged users maintain network access to production systems. The vulnerability's presence in the DDL component suggests that schema modification operations including table creation, alteration, or deletion could be exploited, making it relevant to database administrators and developers who regularly perform structural changes to their database environments.
Mitigation strategies for CVE-2023-21919 primarily focus on immediate patching of affected MySQL Server installations to version 8.0.33 or later, which contains the necessary security fixes. Network segmentation and access controls should be implemented to limit high-privileged user access to database servers, particularly through network protocols that support DDL operations. The implementation of monitoring solutions that can detect unusual patterns in database schema modifications or system instability provides early warning capabilities. Additionally, organizations should consider implementing database activity monitoring and anomaly detection systems that can identify potentially malicious DDL operations before they cause system crashes. The vulnerability's characteristics align with ATT&CK technique T1499.004, which involves network denial of service attacks, and CWE-476, which addresses null pointer dereference conditions that can lead to system instability and crashes. Regular security assessments and penetration testing should be conducted to identify and remediate similar vulnerabilities in database environments, ensuring comprehensive protection against availability-focused attacks that target core database infrastructure components.