CVE-2016-3521 in MySQL Server
Summary
by MITRE
Unspecified vulnerability in Oracle MySQL 5.5.49 and earlier, 5.6.30 and earlier, and 5.7.12 and earlier and MariaDB before 5.5.50, 10.0.x before 10.0.26, and 10.1.x before 10.1.15 allows remote authenticated users to affect availability via vectors related to Server: Types.
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Analysis
by VulDB Data Team • 09/08/2022
This vulnerability affects database systems that are widely deployed across enterprise environments and cloud infrastructures. The unspecified nature of the flaw within Oracle MySQL and MariaDB versions indicates a critical weakness in the server component's handling of data types, which could be exploited by authenticated attackers to disrupt service availability. The vulnerability impacts multiple version ranges including MySQL 5.5.49 and earlier, 5.6.30 and earlier, 5.7.12 and earlier, along with various MariaDB releases before their respective patched versions. These database systems serve as foundational components for countless applications and web services, making the potential impact substantial across different organizational sectors.
The technical flaw resides in the server's processing of data types, specifically within the server component that handles incoming requests from authenticated users. Attackers with valid credentials can craft malicious requests that trigger unexpected behavior in the database server's type handling mechanisms. This typically involves sending specially crafted data or queries that cause the server to enter an inconsistent state, potentially leading to crashes, hangs, or other availability issues. The vulnerability is classified under the Common Weakness Enumeration as a weakness related to improper handling of data types, which falls under CWE-248, indicating an unusual or unexpected exception. The exploitation requires authentication, which means the attack vector is not entirely blind but rather leverages existing user privileges to cause denial of service conditions.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire database infrastructure. Organizations relying on affected database versions may experience unexpected downtime, data access interruptions, and service degradation that affects business operations. The attack scenario typically involves authenticated users who can leverage their privileges to send malformed type-related requests that cause the database server to fail. This vulnerability particularly affects systems where database availability is critical for business operations, including e-commerce platforms, financial systems, and enterprise applications. The potential for cascading failures exists when database unavailability affects dependent applications and services, creating broader operational impacts that extend beyond the immediate database layer.
Organizations should prioritize immediate patching of affected systems to remediate this vulnerability, as the risk of exploitation increases with the presence of authenticated users within the database environment. The mitigation strategy should include comprehensive vulnerability assessment to identify all affected database instances across the organization's infrastructure. Security teams should implement network segmentation to limit access to database servers and enforce strict authentication controls. Monitoring solutions should be enhanced to detect anomalous database behavior patterns that may indicate exploitation attempts. Additionally, regular security audits should be conducted to ensure that all database instances are running patched versions and that proper access controls are maintained. The ATT&CK framework categorizes this vulnerability under the T1499.004 technique for network denial of service, making it a critical concern for enterprise security teams responsible for protecting database infrastructure and maintaining service availability.