CVE-2016-9851 in phpMyAdmin
Summary
by MITRE
An issue was discovered in phpMyAdmin. With a crafted request parameter value it is possible to bypass the logout timeout. All 4.6.x versions (prior to 4.6.5), and 4.4.x versions (prior to 4.4.15.9) are affected.
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Analysis
by VulDB Data Team • 06/25/2019
The vulnerability identified as CVE-2016-9851 represents a critical authentication bypass flaw within phpMyAdmin, a widely used web-based database management tool that serves as the de facto standard interface for MySQL and MariaDB databases in web hosting environments. This vulnerability specifically targets the session management and timeout mechanisms that are fundamental to maintaining secure access to database systems. The issue stems from improper validation of request parameters that control session expiration behavior, creating a pathway for unauthorized users to extend their authenticated sessions beyond the intended timeout periods. Given that phpMyAdmin is deployed in countless production environments and often provides direct access to sensitive database content, this vulnerability poses significant risks to database security and integrity. The flaw affects versions across two major release lines, indicating a widespread impact that would have left numerous installations vulnerable for extended periods.
The technical exploitation of this vulnerability occurs through manipulation of specific request parameters that control session timeout behavior within phpMyAdmin's authentication system. When an attacker crafts a malicious request with carefully constructed parameter values, they can effectively bypass the built-in logout timeout mechanisms that are designed to terminate inactive sessions after a predetermined period. This allows authenticated users to maintain access to database systems beyond the configured security timeouts, potentially enabling extended unauthorized access to sensitive database content, modification of data, or execution of administrative operations. The vulnerability is classified as a weakness in session management and authentication controls, aligning with CWE-613 and CWE-306 categories that address insufficient session expiration and improper authentication mechanisms. The flaw essentially undermines the fundamental security principle of time-based session expiration that is critical for protecting against unauthorized access during periods of inactivity.
The operational impact of CVE-2016-9851 extends far beyond simple session persistence, as it creates opportunities for prolonged unauthorized access to database systems that could result in data breaches, data manipulation, or complete system compromise. Organizations relying on phpMyAdmin for database administration are particularly vulnerable since the tool often provides direct access to production databases containing sensitive customer information, financial records, or proprietary business data. The vulnerability's persistence across multiple versions means that many organizations would have remained exposed for extended periods without awareness of the security gap, potentially allowing attackers to establish persistent access to critical database infrastructure. This type of vulnerability is particularly concerning in environments where database administrators may be away from their workstations for extended periods, as the bypassed timeout mechanisms could allow attackers to maintain access through the authenticated session even when the legitimate user has left the system. The attack vector is relatively simple to execute, requiring only a crafted HTTP request, which makes it particularly dangerous as it can be exploited by attackers with minimal technical expertise.
Organizations should immediately implement mitigations including upgrading to phpMyAdmin versions 4.4.15.9 or 4.6.5, which contain the necessary patches to address the session timeout bypass vulnerability. System administrators should also consider implementing additional security measures such as network-based access controls, monitoring for suspicious authentication patterns, and regular security audits of database management interfaces. The vulnerability demonstrates the importance of proper input validation and session management in web applications, aligning with ATT&CK techniques related to credential access and privilege escalation. Security teams should also review their incident response procedures to ensure they can quickly detect and respond to potential exploitation of this vulnerability. Given that this vulnerability affects the core authentication mechanisms of phpMyAdmin, organizations should consider implementing multi-factor authentication for database access, network segmentation to limit access to database management interfaces, and regular security assessments of web-based database tools. The remediation process should include thorough testing of the patched versions to ensure that legitimate session management functionality remains intact while the security vulnerability is properly addressed.