CVE-2020-2903 in MySQL Server
Summary
by MITRE
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Connection Handling). Supported versions that are affected are 8.0.19 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 • 05/25/2024
The vulnerability identified as CVE-2020-2903 resides within the MySQL Server component known as Server: Connection Handling, representing a critical availability risk that affects MySQL versions 8.0.19 and earlier. This flaw operates at the foundational level of connection management within the database server, where the system's ability to process and maintain client connections becomes compromised. The vulnerability's classification as easily exploitable indicates that attackers with high privileges and network access can leverage this weakness without requiring significant technical expertise or resources, making it particularly dangerous in production environments where database availability is paramount for business operations.
The technical nature of this vulnerability stems from improper handling of connection-related operations that can lead to resource exhaustion or state corruption within the MySQL server process. When exploited, the flaw enables attackers to induce a complete denial of service condition that can either cause the MySQL server to hang indefinitely or trigger repeated crashes that render the database service unavailable to legitimate users. The attack vector requires network access and can be executed through multiple protocols, suggesting that the vulnerability exists at a protocol level rather than being specific to a single communication channel. This characteristic increases the attack surface and makes the vulnerability more difficult to defend against through simple network segmentation measures.
From an operational impact perspective, the consequences of successful exploitation can be severe for organizations relying on MySQL databases for critical business functions. The complete denial of service condition means that database operations cease entirely, potentially affecting applications, services, and workflows that depend on database connectivity. The CVSS 3.0 base score of 4.9, while not classified as critical, represents a significant threat to system availability and can cause substantial business disruption. Organizations may experience downtime that affects customer-facing applications, data processing workflows, and administrative operations. The high privilege requirement suggests that this vulnerability is more likely to be exploited by internal attackers or those who have already compromised other system components, making it particularly concerning for environments with elevated user permissions.
The vulnerability's alignment with CWE-400 indicates it relates to an unchecked resource management issue, where the system fails to properly handle resource allocation and deallocation during connection handling processes. This type of weakness commonly manifests in scenarios where connection limits are not properly enforced or where resource cleanup routines fail to execute correctly. The attack pattern described in the MITRE ATT&CK framework for resource exhaustion techniques demonstrates how attackers can systematically consume available resources to cause service disruption. Organizations should consider implementing connection pooling mechanisms, establishing proper connection limits, and monitoring connection counts as part of their defensive strategy. Additionally, regular patching and version management protocols are essential to mitigate this vulnerability, as Oracle released updates to address the specific connection handling flaws that enabled this attack vector.
The broader implications extend beyond immediate service disruption to include potential data integrity concerns and cascading effects on dependent systems. When database services become unavailable, it can trigger alerts, automated failover processes, and business continuity issues that may not be immediately apparent. The vulnerability's presence in MySQL 8.0.19 and prior versions indicates that organizations should prioritize upgrading to patched versions while implementing monitoring solutions to detect abnormal connection patterns that might indicate exploitation attempts. Network security teams should also consider implementing intrusion detection systems that can identify unusual connection behavior patterns and alert administrators to potential exploitation of this availability-focused vulnerability.