CVE-2021-2012 in MySQL Server
Summary
by MITRE • 01/20/2021
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Security: Privileges). Supported versions that are affected are 8.0.20 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 • 08/09/2025
This vulnerability resides within Oracle MySQL Server's privilege management system, specifically affecting versions 8.0.20 and earlier. The flaw manifests as a security weakness in how the server handles privilege checks, creating an avenue for attackers with high privileges and network access to exploit the system. The vulnerability's classification as easily exploitable indicates that sophisticated attack techniques are not required, making it particularly dangerous in environments where privileged accounts may be compromised or where network exposure exists.
The technical nature of this vulnerability involves a flaw in the server's privilege validation mechanisms that allows an attacker with elevated privileges to manipulate the system's access controls. When exploited, this weakness enables the attacker to cause a denial of service condition by triggering a hang or repeated crashes within the MySQL server process. The vulnerability affects multiple network protocols, increasing its attack surface and making it more difficult to contain. The CVSS score of 4.9 reflects the availability impact, as the primary effect is system unavailability rather than data compromise or privilege escalation beyond the initial access level.
The operational impact of this vulnerability extends beyond simple service disruption, as it can lead to complete system unavailability during attack windows. Organizations running affected MySQL versions face potential business interruption risks, especially in environments where database availability is critical for application functionality. The vulnerability's designation as affecting server security privileges means that any attacker who has already gained high-level access to the system can leverage this weakness to amplify their impact. This creates a particular risk for environments where privilege separation is not properly enforced or where administrative accounts may be exposed to network access.
Mitigation strategies should focus on immediate patching of affected MySQL Server installations to version 8.0.21 or later, which contains the necessary security fixes. Network segmentation and access control measures should be implemented to limit exposure of MySQL servers to untrusted networks. Organizations should also review their privilege management policies and ensure that administrative accounts are properly secured and monitored for unauthorized access. The vulnerability aligns with CWE-284 (Improper Access Control) and may be categorized under ATT&CK technique T1078 (Valid Accounts) and T1499 (Endpoint Denial of Service) in threat modeling frameworks. Regular security assessments and monitoring of MySQL server processes should be implemented to detect potential exploitation attempts and maintain system availability.