CVE-2021-2002 in MySQL Server
Summary
by MITRE • 01/20/2021
Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Replication). Supported versions that are affected are 8.0.22 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 • 02/17/2021
The vulnerability identified as CVE-2021-2002 resides within the MySQL Server replication component of Oracle MySQL, affecting versions 8.0.22 and earlier. This represents a significant security flaw that operates at the server level, specifically targeting the replication functionality that enables database servers to synchronize data across multiple instances. The vulnerability's classification as easily exploitable indicates that attackers with high privileges and network access can leverage this weakness without requiring extensive technical expertise or specialized tools, making it particularly dangerous in production environments where replication is commonly implemented.
The technical nature of this vulnerability manifests as a flaw in how MySQL Server handles certain replication operations, creating conditions where malicious actors can trigger system instability. The flaw specifically impacts the server's ability to maintain stable operations during replication processes, potentially causing complete denial of service scenarios where the MySQL server becomes unresponsive or enters a state of frequent crashes. This behavior aligns with CWE-400, which catalogs weaknesses related to resource management and system stability issues, particularly those that can lead to denial of service conditions through improper handling of system resources or process states.
From an operational standpoint, the impact of this vulnerability extends beyond simple service disruption to encompass potential business continuity risks for organizations relying on MySQL replication for data redundancy and high availability. The CVSS 3.1 score of 4.9 indicates a moderate severity level, but the availability impact rating of high (A:H) suggests that successful exploitation can result in complete system unavailability. Attackers with elevated privileges can exploit this vulnerability through multiple network protocols, indicating that the flaw exists at a fundamental level within the server's network handling mechanisms rather than being limited to specific communication channels. This characteristic makes the vulnerability particularly challenging to defend against as it can be triggered through various attack vectors.
Organizations should prioritize immediate remediation through patching to address this vulnerability, as the combination of high privilege requirements and network access makes it accessible to insiders or attackers who have already compromised other system components. The vulnerability's impact on availability means that traditional monitoring and alerting systems may not immediately detect the instability, as the server may appear to be functioning normally while experiencing internal crashes that prevent proper service delivery. Security teams should implement enhanced monitoring of replication processes and server stability metrics to detect potential exploitation attempts, while also reviewing access controls to ensure that only authorized personnel possess the high privileges required to exploit this vulnerability. The ATT&CK framework categorizes this type of vulnerability under the T1499.004 technique for 'Network Denial of Service' and potentially T1078 for 'Valid Accounts' if exploitation requires elevated privileges, emphasizing the multi-layered approach needed for comprehensive protection against such threats.