CVE-2016-6621 in phpMyAdmin
Summary
by MITRE
The setup script for phpMyAdmin before 4.0.10.19, 4.4.x before 4.4.15.10, and 4.6.x before 4.6.6 allows remote attackers to conduct server-side request forgery (SSRF) attacks via unspecified vectors.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 11/11/2022
The vulnerability identified as CVE-2016-6621 represents a critical server-side request forgery flaw within the phpMyAdmin setup script across multiple affected versions. This issue enables remote attackers to manipulate the application's functionality by tricking it into making unintended requests to internal or external systems. The vulnerability stems from insufficient input validation and sanitization within the setup process, which is a common pattern in web applications that fail to properly validate user-supplied data before processing it. The affected versions include phpMyAdmin 4.0.10.19 and earlier, 4.4.15.10 and earlier, and 4.6.6 and earlier, indicating that this flaw persisted across multiple release branches and affected a significant portion of the user base. The vulnerability is particularly concerning because it occurs during the setup phase, which is typically a critical configuration step where administrators interact with the application to establish database connections and system parameters.
The technical implementation of this SSRF vulnerability involves the setup script accepting user-provided parameters that are then used to construct HTTP requests without proper validation or sanitization. Attackers can exploit this by manipulating input fields that control the target of outgoing requests, potentially allowing them to access internal network resources that should otherwise be protected from external access. The unspecified vectors mentioned in the description suggest that multiple input points within the setup process could be exploited, including but not limited to database connection parameters, proxy settings, or other network-related configuration options. This type of vulnerability directly maps to CWE-918, which specifically addresses server-side request forgery in the context of web applications where user-controllable input is used to construct requests to other systems. The attack vector operates through the principle that applications should never blindly trust user input when constructing network requests, particularly those that could potentially reach internal systems or sensitive endpoints.
The operational impact of this vulnerability extends beyond simple information disclosure and can enable attackers to perform reconnaissance on internal network infrastructure, access sensitive databases, or even escalate their privileges within the target environment. An attacker who successfully exploits this vulnerability could potentially gain access to internal systems that are normally isolated from external networks, effectively bypassing network segmentation controls. This capability makes the vulnerability particularly dangerous in enterprise environments where phpMyAdmin is used to manage database connections, as it could allow unauthorized access to production databases or other critical systems. The vulnerability also demonstrates poor input validation practices that violate fundamental security principles outlined in the OWASP Top Ten, specifically addressing the risk of insecure deserialization and improper input handling. The impact is further amplified because the setup script is typically executed by system administrators who may have elevated privileges, potentially allowing attackers to leverage this vulnerability to gain more significant access than would otherwise be possible.
Mitigation strategies for CVE-2016-6621 require immediate patching of affected phpMyAdmin installations to versions that contain proper input validation and sanitization measures. Organizations should ensure that all phpMyAdmin deployments are updated to the latest stable releases, specifically versions 4.0.10.19, 4.4.15.10, and 4.6.6 or later, depending on their current version. Network-level protections should be implemented through firewall rules that restrict access to the phpMyAdmin setup script, particularly in production environments where it is not actively needed. The implementation of proper input validation, including the use of allowlists for acceptable values and strict sanitization of all user-provided parameters, should be enforced throughout the application. Security monitoring should be enhanced to detect unusual patterns in network requests that might indicate exploitation attempts, with particular attention to requests that attempt to reach internal network addresses or unusual ports. The vulnerability also highlights the importance of following the principle of least privilege in web application development, ensuring that setup scripts and administrative functions are not exposed to unnecessary network access. Additionally, organizations should consider implementing web application firewalls and runtime application self-protection measures to detect and prevent exploitation attempts, as the attack patterns associated with SSRF vulnerabilities often follow predictable patterns that can be identified through behavioral monitoring. The remediation process should include thorough testing to ensure that the patch does not introduce regressions in functionality while also verifying that all network access controls are properly enforced.