CVE-2017-3453 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Optimizer). Supported versions that are affected are 5.5.54 and earlier, 5.6.35 and earlier and 5.7.17 and earlier. Easily "exploitable" vulnerability allows low privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.0 Base Score 6.5 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 12/20/2020
The vulnerability identified as CVE-2017-3453 resides within the MySQL Server component, specifically within the Server: Optimizer subcomponent of Oracle MySQL database systems. This flaw affects multiple version ranges including 5.5.54 and earlier, 5.6.35 and earlier, and 5.7.17 and earlier versions, representing a significant portion of the MySQL server ecosystem. The vulnerability is categorized as easily exploitable, indicating that attackers with minimal technical expertise can leverage this weakness to compromise target systems. The attack vector requires only network access via multiple protocols, making it particularly dangerous as it can be initiated from various network entry points without requiring physical access or specialized tools.
The technical nature of this vulnerability stems from a flaw in the query optimizer module of MySQL Server, which is responsible for determining the most efficient execution plan for database queries. When processing certain malformed or specially crafted queries, the optimizer fails to properly validate input parameters or handle specific edge cases in query execution. This improper handling leads to memory corruption or resource exhaustion conditions that cause the MySQL Server process to become unresponsive or crash entirely. The vulnerability specifically manifests as a denial of service condition where the server becomes unavailable to legitimate users while maintaining the ability to process other requests. The flaw is particularly concerning because it operates at the core optimization layer where database queries are processed, making it a fundamental weakness in the server's operational integrity.
From an operational impact perspective, this vulnerability creates severe availability concerns for organizations relying on MySQL databases, as successful exploitation results in complete denial of service conditions. The vulnerability allows attackers to repeatedly crash the MySQL Server, creating persistent availability issues that can disrupt business operations and data access. The CVSS 3.0 base score of 6.5 indicates a moderate to high severity impact, with the availability impact component rated as high (A:H). This means that while the vulnerability does not provide direct access to data or system compromise, it can effectively shut down database services and prevent legitimate users from accessing critical information. The low privilege requirement (PR:L) means that even users with minimal database permissions can exploit this vulnerability, making it particularly dangerous in environments where database access is granted to multiple users or applications.
The attack surface for this vulnerability extends across multiple network protocols, including TCP/IP connections that MySQL typically uses for database communication. This broad protocol support increases the likelihood of successful exploitation as attackers can target MySQL servers through various network channels. The vulnerability's classification under CWE (Common Weakness Enumeration) would align with weaknesses related to improper input validation and resource management within database query processors. From an ATT&CK framework perspective, this vulnerability maps to techniques involving denial of service attacks and system resource exhaustion, potentially enabling attackers to perform reconnaissance activities or establish persistent access through service disruption. Organizations should prioritize patching affected versions as the primary mitigation strategy, while implementing network segmentation to limit access to database servers and monitoring for unusual connection patterns that might indicate exploitation attempts.
The broader implications of this vulnerability highlight the critical importance of maintaining up-to-date database server software and implementing comprehensive vulnerability management programs. Given that this vulnerability affects multiple major version lines of MySQL, organizations with legacy systems or those that have not kept their database software updated face significant exposure. The ease of exploitation combined with the potential for repeated crashes makes this vulnerability particularly attractive to attackers seeking to disrupt services or establish footholds within network environments. Security teams should consider implementing database activity monitoring solutions that can detect anomalous query patterns or excessive connection attempts that might indicate exploitation attempts. Additionally, regular vulnerability assessments and penetration testing should include evaluation of database server components to identify similar weaknesses that might not yet be publicly disclosed but could represent similar attack vectors.