CVE-2017-3634 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: DML). Supported versions that are affected are 5.6.36 and earlier and 5.7.18 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 • 01/04/2021
The vulnerability identified as CVE-2017-3634 resides within Oracle MySQL Server's DML (Data Manipulation Language) subsystem, representing a critical availability threat that affects multiple versions of the database platform. This flaw manifests in the server's handling of specific data operations and has been classified with a CVSS base score of 6.5, indicating a moderate to high severity impact. The vulnerability operates at the core level of MySQL's database engine, where it processes commands that manipulate stored data through standard SQL operations including insert, update, and delete functions. The affected versions encompass MySQL 5.6.36 and earlier releases, as well as 5.7.18 and earlier iterations, making it a widespread concern across significant portions of the MySQL user base. The attack vector requires only network access via multiple protocols, suggesting that the vulnerability can be exploited from remote locations without requiring physical access to the database server infrastructure.
The technical nature of this vulnerability stems from improper handling of certain data manipulation operations within the MySQL server's memory management and processing routines. When a malicious user with low privileges attempts specific DML operations, the server's internal state becomes corrupted in a manner that leads to system instability. This corruption manifests as either complete system hangs or repeated crashes that can be triggered repeatedly, effectively creating a denial of service condition that prevents legitimate database operations from completing successfully. The flaw operates at the kernel level of the database server, where memory allocation and deallocation processes are handled during the execution of data manipulation commands. Attackers can exploit this weakness by crafting specific SQL statements that, when processed by the vulnerable MySQL server, trigger the memory corruption behavior. The vulnerability's exploitability is considered "easily" achievable due to the minimal privileges required and the straightforward nature of the attack vectors available through standard network protocols.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire database operations and business continuity. Organizations relying on MySQL servers for critical applications face significant risk of operational downtime when this vulnerability is successfully exploited, as the resulting denial of service can prevent legitimate users from accessing or modifying data. The complete system crashes or hangs can persist until manual intervention occurs, requiring database administrators to restart services and potentially recover from backup systems. This vulnerability particularly affects environments where MySQL serves as a backend database for web applications, enterprise systems, or any application requiring reliable data access. The impact on availability is severe, as reflected by the CVSS availability impact rating of high, potentially causing cascading failures in applications that depend on the database for their operations. Organizations may experience revenue loss, customer dissatisfaction, and operational disruption when database services become unavailable due to this vulnerability, especially in mission-critical environments where database uptime is essential.
Mitigation strategies for CVE-2017-3634 should prioritize immediate patching of affected MySQL installations to the latest supported versions that contain the necessary security fixes. System administrators must conduct thorough vulnerability assessments to identify all affected MySQL servers within their network infrastructure and implement mandatory updates as soon as possible. Network segmentation and access controls should be strengthened to limit unnecessary network access to MySQL servers, reducing the attack surface available to potential exploiters. Implementing monitoring solutions that can detect unusual database behavior or repeated crash patterns can provide early warning signs of exploitation attempts. Organizations should also establish robust backup and recovery procedures to minimize downtime during incident response activities. The vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and can be mapped to ATT&CK technique T1499, specifically the "Network Denial of Service" tactic, as it creates persistent availability issues through database server instability. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in database systems, while implementing principle of least privilege access controls can limit the potential impact of successful exploitation attempts.