CVE-2019-2686 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Optimizer). Supported versions that are affected are 8.0.15 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 • 11/05/2024
The vulnerability identified as CVE-2019-2686 resides within the MySQL Server component, specifically within the Server: Optimizer subcomponent of Oracle MySQL. This flaw affects versions 8.0.15 and earlier, representing a significant security concern for database administrators and system operators. The vulnerability operates at the core level of MySQL's query processing capabilities, where the optimizer component is responsible for determining the most efficient execution plan for database queries. The affected version range indicates this issue was present in a critical phase of MySQL's development cycle, potentially affecting numerous production environments that relied on the optimizer's performance enhancements.
The technical nature of this vulnerability stems from improper handling of certain query optimization scenarios that can lead to resource exhaustion or memory corruption within the MySQL server process. Attackers with high privileged access and network connectivity can exploit this weakness through multiple protocols, including TCP/IP connections to the MySQL service port. The vulnerability's classification as easily exploitable means that skilled attackers with elevated privileges can leverage this flaw without requiring complex attack chains or specialized tools. The attack vector operates through network-based communication channels that MySQL servers typically accept, making it particularly dangerous in environments where database services are exposed to external networks.
The operational impact of successfully exploiting CVE-2019-2686 manifests as a complete denial of service condition against the MySQL server instance. This occurs when the vulnerability is triggered, causing the MySQL server to either hang indefinitely or experience frequent crashes that require manual intervention for recovery. The availability impact is rated at CVSS 3.0 score of 4.9, which represents a moderate to high severity threat to system uptime and service availability. The vulnerability's ability to cause repeated crashes means that even a single successful exploitation can result in sustained service disruption, potentially affecting business-critical applications that depend on database availability. This type of attack directly violates the principle of availability in the CIA triad and can have cascading effects throughout enterprise IT infrastructure.
Organizations affected by this vulnerability should prioritize immediate patching of their MySQL server installations to version 8.0.16 or later, which contains the necessary fixes for this optimizer-related flaw. System administrators should also implement network segmentation and access controls to limit exposure of MySQL services to only trusted networks and authorized users. The vulnerability's CVSS scoring indicates that while it requires high privileges for exploitation, the potential for system-wide disruption makes it a critical concern for database security. Security monitoring should include detection of unusual connection patterns or service disruptions that might indicate exploitation attempts. This vulnerability aligns with CWE-121 in the Common Weakness Enumeration catalog, which covers stack-based buffer overflow conditions, and may relate to ATT&CK techniques involving service stoppage or availability disruption. The remediation process should include thorough testing of patched systems to ensure that the fix does not introduce compatibility issues with existing database applications or query workloads.