CVE-2019-2693 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 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 • 11/05/2024
The vulnerability identified as CVE-2019-2693 resides within the MySQL Server component, specifically within the Server: Optimizer subcomponent, affecting MySQL versions 8.0.15 and earlier. This flaw represents a significant security concern as it operates within the core database engine optimization logic, which is fundamental to how MySQL processes and executes database queries. The vulnerability's classification as easily exploitable indicates that attackers with minimal privileges and network access can leverage this weakness to compromise the database server's integrity and availability. The affected version range suggests this issue was present in a critical release phase where optimization features were actively being developed and deployed in enterprise environments.
The technical nature of this vulnerability manifests as a flaw in the query optimization process that can be triggered through multiple network protocols, making it particularly dangerous in diverse network environments where MySQL servers might be accessed via various communication channels. The vulnerability's impact is characterized by the potential to cause complete denial of service conditions, where the MySQL server becomes unresponsive or crashes repeatedly, effectively rendering the database service unavailable to legitimate users and applications. This behavior occurs through a specific mechanism within the optimizer's code path that fails to properly handle certain query execution scenarios, leading to resource exhaustion or invalid memory access patterns that ultimately result in system instability and service disruption.
From an operational perspective, this vulnerability creates a substantial risk for database administrators and security teams as it allows low privileged attackers to inflict significant damage without requiring elevated privileges or complex attack vectors. The CVSS score of 6.5 indicates a moderate to high severity impact, particularly due to the availability impact component that can completely disrupt database operations. The attack vector requiring only network access means that this vulnerability can be exploited from external networks, potentially allowing attackers to target exposed MySQL servers without requiring physical access or complex authentication bypasses. Organizations running affected MySQL versions face the risk of service outages, data unavailability, and potential business disruption that could affect critical applications relying on database connectivity.
The vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and may also relate to CWE-476, pointer dereference without null check, as the optimizer's handling of query execution paths could lead to improper memory management. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers network denial of service attacks, and potentially T1071.004, covering application layer protocol usage, as attackers exploit the server's protocol handling capabilities. Organizations should implement immediate mitigation strategies including applying the relevant Oracle security patches, implementing network segmentation to limit access to MySQL servers, and configuring proper access controls to restrict network exposure. Additionally, monitoring for unusual connection patterns or service disruptions can help detect exploitation attempts, while regular security assessments should verify that all MySQL instances are updated to secure versions that address this specific optimizer flaw.