CVE-2020-2579 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 5.6.46 and prior, 5.7.28 and prior and 8.0.18 and prior. 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 • 03/23/2024
The vulnerability identified as CVE-2020-2579 represents a critical availability risk within Oracle MySQL Server's optimizer component, affecting multiple version branches including 5.6.46 and earlier, 5.7.28 and earlier, and 8.0.18 and earlier. This flaw exists within the server's query optimization engine, which is responsible for determining the most efficient execution plan for database operations. The vulnerability's classification as easily exploitable indicates that attackers with minimal privileges and network access can leverage this weakness to compromise system availability. The attack vector requires network connectivity through multiple protocols, making it accessible across various network configurations and potentially exploitable from external threat actors. The CVSS score of 6.5 reflects the high impact on availability, specifically targeting the ability to cause complete denial of service through system hangs or repeated crashes.
The technical nature of this vulnerability stems from improper handling within the MySQL Server's optimizer module, where specific query patterns or conditions can trigger memory corruption or resource exhaustion scenarios. When exploited, the vulnerability allows an attacker to craft malicious queries that, when processed by the optimizer, cause the MySQL server process to become unresponsive or crash repeatedly. This behavior constitutes a complete denial of service condition where legitimate database operations cannot proceed, effectively rendering the database server non-functional. The low privilege requirement means that even users with minimal database permissions can potentially execute this attack, making it particularly dangerous in environments where access controls may not be strictly enforced. The vulnerability's impact extends beyond simple service interruption to include potential data integrity concerns if the crashes occur during critical transaction processing.
The operational impact of CVE-2020-2579 is substantial for organizations relying on MySQL Server for critical database operations. System administrators face the challenge of maintaining database availability while dealing with potential service disruptions that can affect multiple applications dependent on the database. The vulnerability's ability to cause repeated crashes means that even if initial exploitation is detected and mitigated, the system may remain unstable until proper patches are applied. Organizations may experience significant downtime during the patching process, particularly in environments where database restarts are required for vulnerability remediation. The attack's network accessibility increases the attack surface significantly, potentially exposing systems to remote exploitation without requiring physical access or elevated privileges. This vulnerability particularly impacts organizations with legacy MySQL installations that may not have been regularly updated, creating extended windows of exposure.
Mitigation strategies for CVE-2020-2579 should prioritize immediate patching of affected MySQL versions to the latest available releases, which address the underlying optimizer flaw. Organizations should implement network segmentation and access controls to limit exposure of MySQL servers to untrusted networks, reducing the attack surface for potential exploitation. Database administrators should consider implementing connection throttling and query monitoring mechanisms to detect anomalous query patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-129, which addresses improper validation of array indices, and may relate to ATT&CK technique T1499.004 for network denial of service attacks. Regular security assessments should be conducted to identify and remediate similar vulnerabilities in database systems, particularly focusing on query processing components that handle user input. Additionally, implementing database firewalls and query filtering systems can provide additional layers of protection against malicious query execution patterns that could trigger this vulnerability.