CVE-2015-2571 in MySQL Server
Summary
by MITRE
Unspecified vulnerability in Oracle MySQL Server 5.5.42 and earlier, and 5.6.23 and earlier, allows remote authenticated users to affect availability via unknown vectors related to Server : Optimizer.
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Analysis
by VulDB Data Team • 05/07/2022
The vulnerability identified as CVE-2015-2571 represents a critical weakness within Oracle MySQL Server that affects multiple version ranges including 5.5.42 and earlier releases, as well as 5.6.23 and earlier versions. This issue resides within the Server Optimizer component of the database system, which is responsible for query execution planning and optimization. The vulnerability specifically impacts authenticated remote users who can leverage this weakness to disrupt system availability, making it particularly dangerous in production environments where database stability is paramount. The unspecified nature of the exact attack vectors means that the precise mechanism by which the availability impact is achieved remains partially obscured, though the classification as an optimizer-related vulnerability suggests potential exploitation through malformed queries or specific query patterns that cause the optimizer to fail or consume excessive resources.
The technical flaw within the MySQL Server Optimizer component demonstrates a fundamental weakness in how the system handles certain query processing scenarios that could lead to resource exhaustion or system instability. This type of vulnerability typically manifests when the optimizer encounters query structures or combinations that trigger unexpected behavior in the internal processing logic. The impact on availability suggests that successful exploitation could result in database service disruption, denial of service conditions, or potentially complete system crashes that would require manual intervention to restore normal operations. Given that the vulnerability affects the core optimizer functionality, any exploitation attempts would likely be difficult to detect through standard monitoring mechanisms since the behavior would appear to be legitimate query processing rather than malicious activity.
From an operational perspective, this vulnerability presents significant risks to organizations relying on MySQL Server for critical database operations, particularly those with high availability requirements or systems where database uptime is essential for business continuity. The fact that remote authenticated users can exploit this weakness means that attackers with valid credentials could potentially cause service disruption, leading to data access issues, application downtime, and potential financial losses. Organizations running affected MySQL versions must consider the broader implications of this vulnerability within their security posture, as it could be leveraged as part of a larger attack chain or could be combined with other vulnerabilities to create more severe impacts. The remote aspect of the vulnerability means that attackers do not require physical access to the system, making it particularly concerning for cloud environments and distributed database deployments.
Mitigation strategies for CVE-2015-2571 should prioritize immediate patching of affected MySQL Server installations to the latest available versions that contain fixes for the optimizer-related vulnerability. Organizations should implement network segmentation and access controls to limit the number of authenticated users who can connect to database servers, thereby reducing the attack surface. Monitoring and logging of database query activity should be enhanced to detect unusual query patterns that might indicate exploitation attempts, though this approach may be limited by the unspecified nature of the attack vectors. Security teams should also consider implementing database firewalls or query filtering mechanisms that can help identify and block potentially malicious query structures before they reach the optimizer component. Additionally, regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in database configurations and to ensure that all systems remain protected against known exploits. This vulnerability aligns with CWE-119 which addresses weaknesses in memory management and data handling, and could potentially map to ATT&CK technique T1499 for availability disruption through database service interruption.