CVE-2022-21569 in MySQL Server
Summary
by MITRE • 07/20/2022
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.29 and prior. Easily exploitable vulnerability allows low 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 6.5 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 05/18/2025
The vulnerability identified as CVE-2022-21569 represents a critical availability threat within Oracle MySQL Server's optimizer component, affecting versions 8.0.29 and earlier. This flaw resides in the server's query optimization engine, which is responsible for determining the most efficient execution plan for database operations. The vulnerability manifests when the optimizer encounters specific query patterns that trigger an internal error condition, leading to system instability. The attack vector requires only network access from a low-privileged user, making it particularly dangerous as it can be exploited without elevated credentials or specialized access rights. This characteristic places the vulnerability in the category of remotely exploitable issues that can be leveraged by attackers with minimal privileges to disrupt database services.
The technical nature of this vulnerability stems from improper handling of certain optimizer states during query execution, specifically within the execution plan generation phase. When a malicious query is processed through the affected optimizer component, it can cause the server to enter an inconsistent state that results in either a complete hang or repeated crashes. The flaw does not permit data exfiltration or unauthorized access to database contents, but rather focuses on service disruption through resource exhaustion or system lockup conditions. The vulnerability's classification as easily exploitable indicates that the attack mechanics are straightforward and do not require complex exploit development or extensive reconnaissance. This characteristic significantly increases the risk profile as attackers can readily develop or obtain working exploits.
The operational impact of CVE-2022-21569 extends beyond simple service interruption, potentially causing significant business disruption for organizations relying on MySQL databases. The availability impact score of 6.5 reflects the potential for complete denial of service conditions that can affect critical database operations across multiple applications. Organizations using affected MySQL versions face the risk of sustained outages that can cascade through dependent systems, affecting user access, application functionality, and overall operational continuity. The vulnerability affects multiple network protocols, including TCP/IP connections, which means that any application communicating with the database server over these channels could be exploited. This multi-protocol exposure increases the attack surface and makes the vulnerability particularly challenging to defend against in complex network environments.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected MySQL server installations to version 8.0.30 or later, which contains the necessary fixes to address the optimizer flaw. Organizations should also implement network segmentation and access controls to limit exposure of database servers to untrusted networks, although this approach provides only partial protection given the low privilege requirements for exploitation. Database administrators should consider implementing query monitoring and rate limiting mechanisms to detect and prevent exploitation attempts, though these measures may not fully prevent the vulnerability from being triggered. The vulnerability aligns with CWE-121, which describes buffer overflow conditions, and maps to ATT&CK technique T1499.004 for network denial of service attacks, highlighting the strategic importance of addressing availability threats in database infrastructure. Regular security assessments and vulnerability scanning should be conducted to identify other potentially affected components within the database ecosystem, ensuring comprehensive protection against similar threats.