CVE-2016-0611 in MySQL Server
Summary
by MITRE
Unspecified vulnerability in Oracle MySQL 5.6.27 and earlier and 5.7.9 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-2016-0611 represents a critical weakness in Oracle MySQL database systems affecting versions 5.6.27 and earlier, as well as 5.7.9 and prior releases. This issue falls under the category of availability impact, meaning that successful exploitation could lead to service disruption or complete unavailability of database services. The vulnerability specifically relates to the optimizer component within MySQL, which is responsible for determining the most efficient execution plan for database queries. The optimizer plays a crucial role in database performance and resource utilization, making any weakness in this area potentially devastating for database operations.
The technical nature of this vulnerability stems from unspecified vectors within the optimizer module that can be triggered by authenticated remote attackers. This means that an attacker must first establish valid credentials to access the MySQL server, but once authenticated, they can leverage this weakness to compromise system availability. The optimizer's role in query execution makes this particularly dangerous because attackers could craft specific queries or combinations of queries that would cause the optimizer to enter an unstable state or consume excessive system resources. The unspecified nature of the vectors suggests that the vulnerability may manifest through multiple attack paths or that the exact mechanisms have not been fully disclosed in public reports.
From an operational impact perspective, this vulnerability presents a significant risk to database availability and business continuity. When the optimizer becomes compromised, it can lead to database server crashes, query timeouts, or complete service outages that can affect multiple applications depending on the database. The authenticated requirement reduces the attack surface compared to unauthenticated vulnerabilities but does not eliminate the risk entirely since database credentials are often widely distributed within organizations. The impact extends beyond simple availability issues as database unavailability can cascade through entire application ecosystems, affecting user access, transaction processing, and overall system reliability.
Organizations affected by this vulnerability should implement immediate mitigation strategies including applying the appropriate Oracle security patches and updates as soon as they become available. Network segmentation and access controls should be strengthened to limit the number of authenticated users who can reach database servers. Monitoring should be enhanced to detect unusual query patterns or resource consumption that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1499 which involves disrupting availability of systems and data, and may also relate to CWE-400 which covers unspecified vulnerabilities in resource management. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other database components, as the optimizer module represents a critical attack surface that requires ongoing attention and monitoring for potential exploitation vectors.