CVE-2020-14786 in MySQL Server
Summary
by MITRE • 10/21/2020
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: PS). Supported versions that are affected are 8.0.21 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 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/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 • 08/08/2025
The vulnerability identified as CVE-2020-14786 represents a significant availability risk within Oracle MySQL Server versions 8.0.21 and earlier. This flaw exists within the Server: PS component of the MySQL ecosystem and demonstrates how even seemingly minor implementation issues can lead to catastrophic system failures. The vulnerability's classification as easily exploitable indicates that attackers with high privileged network access can leverage this weakness without requiring extensive technical expertise or specialized tools. The attack vector specifically involves network-based access through multiple protocols, making it particularly concerning for environments where MySQL servers are exposed to external networks or where internal network segmentation is inadequate.
The technical nature of this vulnerability manifests as a condition that allows attackers to cause either a hang or frequently repeatable crashes in the MySQL Server instance. This behavior directly maps to a denial of service scenario where the database service becomes unavailable to legitimate users and applications. The complete DOS capability means that the server may become unresponsive for extended periods or require manual intervention to restore normal operations. The vulnerability's impact on availability is quantified by the CVSS 3.1 Base Score of 4.9, which reflects the severity of the potential disruption to database services. The vector analysis shows AV:N (network access), AC:L (low attack complexity), PR:H (high privilege requirement), and UI:N (no user interaction required), indicating that while attackers need elevated privileges, the actual exploitation process is straightforward.
From an operational perspective, this vulnerability creates substantial risk for organizations relying on MySQL databases for critical business operations. The potential for complete service disruption means that applications depending on database connectivity may experience extended downtime, potentially leading to significant financial losses and reputational damage. The requirement for high privileged access somewhat limits the attack surface, but organizations with compromised accounts or insider threats face particular risk. The vulnerability's presence in MySQL Server versions up to 8.0.21 indicates that a substantial portion of deployed MySQL installations may be affected, particularly those that have not received timely updates or patches. The fact that this vulnerability affects multiple protocols suggests that attackers can exploit it through various communication channels, increasing the overall attack surface.
Organizations should prioritize immediate patching of affected MySQL Server installations to address this vulnerability. The remediation process should include comprehensive testing of patches in staging environments before deployment to production systems. Security teams should also implement network segmentation measures to limit access to MySQL servers and ensure that only authorized network segments can communicate with database services. Monitoring systems should be enhanced to detect unusual patterns of database service disruption or connection failures that might indicate exploitation attempts. The vulnerability's classification under CWE categories related to resource management and availability impacts aligns with common attack patterns documented in the ATT&CK framework, particularly those involving service disruption and availability attacks. Additionally, organizations should review their privileged access controls and implement principle of least privilege to minimize the potential impact of compromised accounts. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in database configurations and network architectures that could provide alternative attack paths.