CVE-2014-6520 in MySQL Server
Summary
by MITRE
Unspecified vulnerability in Oracle MySQL Server 5.5.38 and earlier allows remote authenticated users to affect availability via vectors related to SERVER:DDL.
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Analysis
by VulDB Data Team • 02/23/2022
The vulnerability identified as CVE-2014-6520 represents a significant availability risk within Oracle MySQL Server versions 5.5.38 and earlier. This weakness falls under the broader category of denial of service attacks that specifically target the database server's data definition language processing capabilities. The vulnerability affects authenticated users who can leverage specific DDL operations to disrupt the normal functioning of the MySQL server, potentially leading to complete service unavailability. The unspecified nature of the exact flaw makes this vulnerability particularly concerning as it may encompass multiple related attack vectors within the server's DDL handling mechanisms.
The technical flaw manifests when authenticated users execute certain data definition language commands that trigger unexpected behavior in the MySQL server's processing pipeline. These commands typically involve operations that modify database schema structures, create or alter tables, or manage database objects. The vulnerability exploits weaknesses in how the server validates and processes these DDL statements, allowing malicious users to craft inputs that cause the server to crash, become unresponsive, or enter an inconsistent state. This behavior directly violates the principle of graceful degradation and can be exploited to deny legitimate users access to database services.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the entire database infrastructure. When exploited successfully, the vulnerability can cause the MySQL server process to terminate unexpectedly or enter a state where it cannot properly handle additional requests. This affects not only the immediate database operations but can also impact applications that depend on the database for their functionality. The availability aspect is particularly severe because database servers are critical infrastructure components, and their unavailability can cascade into broader system failures affecting multiple dependent services and applications. Organizations may experience data access interruptions, application downtime, and potential data consistency issues that require extensive recovery procedures.
Mitigation strategies for CVE-2014-6520 should prioritize immediate patching of affected MySQL Server installations to the latest available versions that contain the necessary security fixes. System administrators must ensure that all MySQL instances are updated to versions that address this specific vulnerability, as Oracle typically releases patches that resolve these types of server-side flaws. Additionally, implementing network segmentation and access controls can limit the exposure of MySQL servers to untrusted users, while monitoring solutions should be deployed to detect unusual DDL operations that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1499.004 for network denial of service and CWE-400 for unchecked error conditions, emphasizing the need for robust error handling and input validation in database server implementations. Organizations should also consider implementing database activity monitoring and anomaly detection systems to identify potential exploitation attempts before they can cause significant damage to service availability.