CVE-2021-2011 in MySQL Client
Summary
by MITRE • 01/20/2021
Vulnerability in the MySQL Client product of Oracle MySQL (component: C API). Supported versions that are affected are 5.7.32 and prior and 8.0.22 and prior. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise MySQL Client. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Client. CVSS 3.1 Base Score 5.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/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-2021-2011 represents a significant availability risk within Oracle MySQL Client implementations, specifically affecting the C Application Programming Interface component. This flaw manifests in versions 5.7.32 and earlier, as well as 8.0.22 and prior, indicating it spans multiple major release lines and affects a substantial portion of deployed MySQL client installations. The vulnerability's classification as difficult to exploit suggests that while the attack vector requires some technical knowledge, the potential impact on system availability makes it particularly concerning for production environments that rely on MySQL connectivity.
The technical nature of this vulnerability allows an unauthenticated attacker to compromise the MySQL Client through multiple network protocols, demonstrating the broad scope of potential attack surfaces. The attack requires only network access without authentication credentials, making it accessible to any attacker who can reach the target system. This characteristic aligns with CWE-20, which describes improper input validation as a common root cause for such vulnerabilities, where the client fails to properly validate or sanitize incoming data streams from network connections.
The operational impact of CVE-2021-2011 is severe, as successful exploitation results in a complete denial of service condition where the MySQL Client becomes unresponsive or repeatedly crashes. This behavior creates a persistent availability issue that can disrupt database operations and applications dependent on MySQL connectivity. The CVSS score of 5.9 indicates a medium severity vulnerability with high availability impact, suggesting that organizations should prioritize remediation efforts to prevent potential service disruption. The vulnerability's ability to cause repeated crashes or hangs demonstrates that it affects the client's stability rather than just its security posture.
From a cybersecurity perspective, this vulnerability aligns with ATT&CK techniques related to service stoppage and availability disruption, where adversaries seek to compromise system resources to prevent legitimate use. The multi-protocol attack surface makes this vulnerability particularly dangerous as it can be exploited through various network communication channels, including TCP/IP and UDP protocols commonly used in database communications. Organizations should consider implementing network segmentation and access controls to limit exposure to this vulnerability, while also monitoring for potential exploitation attempts that might manifest as connection drops or service disruptions.
Mitigation strategies should focus on immediate patching of affected MySQL client installations to versions that address this specific vulnerability. System administrators should also implement network monitoring solutions to detect unusual connection patterns or service disruptions that might indicate exploitation attempts. Additionally, organizations should consider deploying intrusion detection systems that can identify network traffic patterns consistent with this vulnerability's exploitation methods, particularly focusing on malformed packets or unexpected connection terminations that might precede client crashes. The remediation process should include comprehensive testing of patched systems to ensure that the vulnerability has been properly addressed without introducing compatibility issues with existing applications.