CVE-2019-2950 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.16 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 • 01/15/2024
The vulnerability identified as CVE-2019-2950 represents a critical availability threat within Oracle MySQL Server's optimizer component, specifically affecting versions 8.0.16 and earlier. This flaw resides in the server's query optimization logic where a carefully crafted malicious query can trigger a denial of service condition that leads to complete system unavailability. The vulnerability operates at the core execution layer of the database engine, making it particularly dangerous as it can be exploited by attackers who already possess high-privilege credentials and network access to the target system. The attack vector is particularly concerning because it can be initiated through multiple network protocols, expanding the potential attack surface significantly.
The technical nature of this vulnerability stems from improper handling of certain query execution paths within the MySQL optimizer module. When a maliciously constructed query is processed, the optimizer enters an infinite loop or encounters a condition that causes the server to crash repeatedly, resulting in a complete denial of service. This behavior manifests as either a system hang or a frequently repeatable crash pattern that prevents legitimate database operations from executing successfully. The flaw essentially creates a condition where the server cannot recover from the malformed query processing, forcing administrators to manually restart the service or wait for the system to become unresponsive.
From an operational perspective, this vulnerability presents significant risks to database availability and business continuity. Organizations running affected MySQL versions face potential downtime that could impact critical applications relying on database services, particularly in environments where database availability is paramount for business operations. The CVSS 3.0 score of 4.9 indicates a moderate to high severity impact, with the availability impact being the primary concern. The fact that this vulnerability requires only high-privilege access makes it particularly dangerous in environments where administrative credentials may be compromised, as the attacker can cause persistent service disruption without requiring additional authentication steps.
The vulnerability aligns with CWE-121, which addresses buffer overflow conditions, and maps to ATT&CK technique T1499.004 for network denial of service attacks. Organizations should prioritize immediate patching of affected systems to mitigate this risk, as the vulnerability can be exploited remotely by authenticated users with sufficient privileges. The recommended mitigation strategy involves upgrading to MySQL Server version 8.0.17 or later, which contains the necessary fixes to prevent the optimizer from entering problematic execution states. Additionally, implementing network segmentation and access controls can help reduce the attack surface by limiting which users can access the database server with high privileges, thereby reducing the likelihood of successful exploitation.