CVE-2020-7621 in strong-nginx-controller
Summary
by MITRE
strong-nginx-controller through 1.0.2 is vulnerable to Command Injection. It allows execution of arbitrary command as part of the '_nginxCmd()' function.
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Analysis
by VulDB Data Team • 05/13/2024
The vulnerability identified as CVE-2020-7621 affects the strong-nginx-controller software version 1.0.2 and earlier, presenting a critical command injection flaw that enables unauthorized execution of arbitrary commands. This vulnerability resides within the _nginxCmd() function, which serves as a critical interface for processing nginx commands. The flaw arises from insufficient input validation and sanitization mechanisms that fail to properly handle user-supplied data, creating an attack surface where malicious actors can inject command sequences that get executed with the privileges of the affected application.
The technical implementation of this vulnerability demonstrates a classic command injection weakness that aligns with CWE-77, which specifically addresses improper neutralization of special elements used in commands. The _nginxCmd() function likely constructs system commands by concatenating user-provided parameters directly into command strings without adequate sanitization or parameterization. This design flaw allows attackers to manipulate input fields that are subsequently passed to system execution functions, enabling them to inject malicious commands that execute within the context of the nginx controller process. The vulnerability's impact is amplified by the fact that nginx controllers often run with elevated privileges, potentially allowing attackers to execute commands with system-level access.
Operationally, this vulnerability poses significant risks to organizations relying on strong-nginx-controller for their nginx management infrastructure. Attackers exploiting this flaw could gain complete control over the affected system, potentially leading to data exfiltration, system compromise, or lateral movement within the network. The command injection could enable adversaries to install backdoors, modify configuration files, or even escalate privileges to root access depending on the execution context. The vulnerability's exploitation requires minimal sophistication, making it particularly dangerous as it can be leveraged by attackers with basic command injection knowledge. Organizations using this controller in production environments face immediate risk of compromise, especially if the controller is exposed to untrusted networks or user inputs.
Mitigation strategies for CVE-2020-7621 should prioritize immediate patching of the strong-nginx-controller software to version 1.0.3 or later, which contains the necessary fixes for input validation. Organizations should implement strict input sanitization and validation mechanisms to prevent command injection attempts, ensuring that all user-supplied data is properly escaped or parameterized before being used in system command construction. Network segmentation and access controls should be enforced to limit exposure of the controller to trusted networks only, while monitoring systems should be configured to detect anomalous command execution patterns. The implementation of principle of least privilege should be enforced, ensuring the controller process runs with minimal required permissions. Additionally, organizations should conduct comprehensive security assessments of their nginx controller configurations and implement regular vulnerability scanning to identify similar issues in other components of their infrastructure, aligning with ATT&CK framework's command and control tactics that emphasize the exploitation of such vulnerabilities for persistent access and lateral movement within compromised environments.