CVE-2018-2646 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: DML). Supported versions that are affected are 5.7.20 and prior. Easily exploitable vulnerability allows high 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 4.9 (Availability impacts). CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).
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Analysis
by VulDB Data Team • 01/31/2021
The vulnerability identified as CVE-2018-2646 resides within the MySQL Server component, specifically within the Server: DML subcomponent, affecting MySQL versions 5.7.20 and earlier. This weakness represents a significant security concern for database administrators and system operators who rely on MySQL as their primary database management system. The vulnerability operates at a fundamental level within the database engine's data manipulation language processing capabilities, which forms the backbone of database operations including inserts, updates, and deletes.
The technical flaw manifests as a condition where a high privileged attacker with network access can exploit this weakness to cause a complete denial of service against the MySQL server. The vulnerability's exploitability is classified as easily accessible, meaning that sophisticated attack techniques are not required to leverage this weakness. The attack vector requires only network connectivity and elevated privileges, which significantly broadens the potential attack surface. This vulnerability operates through multiple protocols, indicating that it affects various communication channels that MySQL servers may utilize, including TCP/IP connections and other network protocols.
The operational impact of this vulnerability is severe as it can result in unauthorized ability to cause either a hang or frequently repeatable crash of the MySQL server, effectively leading to complete denial of service. This means that legitimate users and applications attempting to access the database will be unable to perform their operations, resulting in business disruption and potential data unavailability. The CVSS 3.0 base score of 4.9 indicates a medium severity impact, but the availability impact rating of high (A:H) demonstrates the critical nature of the potential consequences. The vulnerability affects the availability aspect of the CIA triad, making it particularly dangerous for systems where database uptime is critical.
From a cybersecurity perspective, this vulnerability aligns with CWE-122 which describes "Heap Overflow" conditions, though the specific mechanism may involve other memory management issues within the DML processing subsystem. The attack pattern associated with this vulnerability fits within the ATT&CK framework under the "Execution" and "Denial of Service" tactics, as attackers can leverage this weakness to execute malicious operations that ultimately result in system unavailability. The requirement for high privileged access indicates that this vulnerability is likely to be exploited by insider threats or attackers who have already compromised administrative credentials, making it particularly concerning for environments where privilege escalation is a potential concern.
Organizations should implement immediate mitigations including updating to MySQL versions 5.7.21 or later, where this vulnerability has been addressed through patches and code modifications. Network segmentation and access controls should be enhanced to limit network access to MySQL servers, particularly for administrative functions. Monitoring systems should be configured to detect unusual patterns of database server behavior that might indicate exploitation attempts. Additionally, implementing robust privilege management practices and regular security audits can help reduce the risk of exploitation. The vulnerability demonstrates the importance of maintaining up-to-date database software and highlights the need for comprehensive security testing of database components, particularly those handling data manipulation operations which form the core of database functionality.