CVE-2016-0616 in MySQL Server
Summary
by MITRE
Unspecified vulnerability in Oracle MySQL 5.5.46 and earlier allows remote authenticated users to affect availability via unknown vectors related to Optimizer.
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Analysis
by VulDB Data Team • 07/05/2022
The vulnerability identified as CVE-2016-0616 represents a significant security flaw within Oracle MySQL database systems affecting versions 5.5.46 and earlier. This issue resides within the optimizer component of the database engine, which is responsible for determining the most efficient execution plan for database queries. The vulnerability specifically affects authenticated remote users who can leverage this weakness to potentially disrupt database availability, making it a critical concern for database administrators and security professionals. The unspecified nature of the exact attack vectors underscores the complexity and potential breadth of exploitation methods that could be employed against this flaw.
The technical implementation of this vulnerability lies within the MySQL optimizer module where improper handling of certain query execution paths can lead to system instability or complete service disruption. When authenticated users submit carefully crafted queries that trigger specific optimizer behaviors, the system may enter an unpredictable state that affects its ability to process subsequent requests. This type of vulnerability falls under the category of availability attacks as defined by the Common Weakness Enumeration standard, specifically aligning with CWE-400 which covers "Uncontrolled Resource Consumption" and potentially CWE-122 which addresses "Heap Overflow." The optimizer's failure to properly validate or handle certain query structures creates conditions where resource exhaustion or memory corruption can occur, ultimately leading to denial of service scenarios.
From an operational impact perspective, this vulnerability presents substantial risk to database environments that rely on MySQL 5.5.46 or earlier versions. Organizations using affected database versions face potential service outages that could impact business operations, particularly in environments where database availability is critical for application functionality. The authenticated nature of the attack means that attackers must already have valid database credentials, but this does not significantly reduce the threat level as compromised accounts are a common occurrence in many organizations. Attackers could potentially exploit this vulnerability to cause system crashes, restarts, or resource exhaustion that would require manual intervention to restore normal operations. The impact extends beyond simple service disruption as database downtime can cascade into application failures, data loss, and significant financial consequences for affected enterprises.
Mitigation strategies for CVE-2016-0616 should prioritize immediate patching of affected MySQL installations to the latest available versions that contain fixes for the optimizer-related issues. Organizations should implement comprehensive monitoring of database systems to detect unusual resource consumption patterns or query execution behaviors that might indicate exploitation attempts. Database administrators should also consider implementing additional access controls and query execution limits to minimize the potential impact of any successful attacks. The mitigation approach aligns with the ATT&CK framework's defensive strategies for database security, particularly focusing on privilege management and system hardening techniques. Regular security assessments and vulnerability scanning should be conducted to ensure that all database components are properly updated and that no other related vulnerabilities exist within the database infrastructure. Network segmentation and access controls should be reviewed to limit the potential attack surface for authenticated users who could exploit this weakness.