CVE-2016-0639 in MySQL Server
Summary
by MITRE
Unspecified vulnerability in Oracle MySQL 5.6.29 and earlier and 5.7.11 and earlier allows remote attackers to affect confidentiality, integrity, and availability via vectors related to Pluggable Authentication.
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Analysis
by VulDB Data Team • 07/26/2022
The vulnerability identified as CVE-2016-0639 represents a critical security flaw within Oracle MySQL database systems affecting versions 5.6.29 and earlier, as well as 5.7.11 and earlier. This issue stems from weaknesses in the Pluggable Authentication architecture, which is a core component responsible for managing user authentication and authorization within the database environment. The unspecified nature of the vulnerability indicates that the exact technical mechanism remains undisclosed, but the impact spans all three fundamental principles of information security including confidentiality, integrity, and availability. The vulnerability exists within the authentication framework that allows external entities to potentially compromise database systems through malicious authentication attempts or exploitation of the pluggable authentication modules.
The technical flaw resides in how MySQL handles authentication requests when using pluggable authentication mechanisms, which are designed to provide flexible authentication methods beyond the standard MySQL authentication. This architecture allows database administrators to implement custom authentication plugins that can handle various authentication protocols and methods. However, the vulnerability creates an opportunity for remote attackers to manipulate the authentication process, potentially leading to unauthorized access to database resources. The attack vector typically involves exploiting weaknesses in the authentication module handling, which could allow adversaries to bypass authentication mechanisms, escalate privileges, or disrupt normal database operations. This vulnerability is particularly concerning because it affects the foundational authentication infrastructure that protects database access controls.
The operational impact of CVE-2016-0639 extends far beyond simple unauthorized access, as it compromises the fundamental security posture of MySQL database deployments. Attackers exploiting this vulnerability can potentially gain read access to sensitive database content, modify or delete critical data, and disrupt database availability through various attack methods. The confidentiality aspect means that sensitive information stored in databases could be exposed to unauthorized parties, while integrity violations could result in data corruption or manipulation that goes undetected. Availability impacts occur when attackers can cause denial of service conditions or system disruptions that prevent legitimate users from accessing database resources. Organizations using affected MySQL versions face significant risk of data breaches, compliance violations, and operational disruptions that can affect business continuity and regulatory compliance.
Mitigation strategies for CVE-2016-0639 primarily focus on immediate patching and system updates to address the underlying authentication vulnerabilities. Organizations should prioritize upgrading to MySQL versions that have been patched to resolve this issue, specifically versions 5.6.30 and 5.7.12 or later, which contain the necessary security fixes. Additionally, implementing network segmentation and access controls can help limit exposure by restricting direct network access to MySQL instances from untrusted networks. Database administrators should also review and strengthen authentication configurations, disable unnecessary authentication plugins, and implement monitoring solutions to detect suspicious authentication attempts. The vulnerability aligns with CWE-284 Access Control Issues and can be categorized under ATT&CK technique T1078 Valid Accounts, as it potentially enables adversaries to establish persistent access through compromised authentication mechanisms. Regular security assessments and vulnerability scanning should be conducted to ensure that all database systems remain protected against similar authentication-related threats.