CVE-2016-5440 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 administrators to affect availability via vectors related to Server: RBR.
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Analysis
by VulDB Data Team • 09/08/2022
The vulnerability identified as CVE-2016-5440 represents a significant availability threat within database management systems, specifically affecting Oracle MySQL and MariaDB implementations. This issue resides within the replication mechanisms of these database servers, where the flaw manifests during the handling of row-based replication operations. The vulnerability affects multiple versions across different product lines, indicating a widespread exposure that impacts both commercial Oracle MySQL deployments and open-source MariaDB implementations. The affected versions include MySQL 5.5.49 and earlier, 5.6.30 and earlier, and 5.7.12 and earlier, alongside MariaDB versions before 5.5.50, 10.0.x before 10.0.26, and 10.1.x before 10.1.15, demonstrating the comprehensive nature of this security weakness.
The technical nature of this vulnerability lies within the server-side handling of row-based replication operations, where remote administrative users can exploit specific conditions to cause system instability or complete service unavailability. This type of vulnerability falls under the category of availability attacks as defined by the Common Weakness Enumeration framework, specifically relating to weaknesses that can cause denial of service conditions. The exploitation mechanism involves manipulating replication-related data structures during the processing of row-based replication events, which can lead to memory corruption or resource exhaustion conditions. The attack vector is particularly concerning because it targets administrative users who typically have elevated privileges, allowing them to potentially disrupt database operations without requiring complex attack chains or additional exploitation techniques.
From an operational impact perspective, this vulnerability poses a severe risk to database availability and business continuity, particularly in environments where high availability and consistent database operations are critical. The ability for remote administrators to affect availability means that even legitimate privileged users could inadvertently or maliciously cause service disruption, potentially leading to extended downtime for database services. Organizations relying on replication mechanisms for data synchronization, backup operations, or high availability setups face the greatest risk from this vulnerability. The impact extends beyond simple service interruption to potentially affect data consistency and recovery operations, as replication failures can cascade into broader system issues. This vulnerability aligns with ATT&CK techniques related to denial of service and privilege escalation, as it can be leveraged to cause system instability while potentially maintaining administrative access levels.
The remediation approach for CVE-2016-5440 requires immediate attention through version upgrades to patched releases of both Oracle MySQL and MariaDB implementations. Organizations should prioritize updating their database servers to versions that contain the specific fixes for replication-related memory handling issues. The patching process should include thorough testing in staging environments to ensure compatibility with existing applications and replication configurations. Network segmentation and access controls should be implemented to limit administrative access to database servers, reducing the attack surface for potential exploitation. Additionally, monitoring systems should be enhanced to detect unusual replication patterns or resource consumption spikes that might indicate exploitation attempts. Organizations should also review their replication configurations and implement proper access controls for administrative accounts to minimize the risk of unauthorized exploitation. The vulnerability highlights the importance of maintaining up-to-date database implementations and the critical need for regular security assessments of database server configurations.