CVE-2018-21106 in R7800
Summary
by MITRE
NETGEAR R7800 devices before 1.0.2.60 are affected by command injection by an authenticated user.
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Analysis
by VulDB Data Team • 06/02/2024
The vulnerability identified as CVE-2018-21106 affects NETGEAR R7800 wireless routers running firmware versions prior to 1.0.2.60, representing a critical command injection flaw that enables authenticated users to execute arbitrary commands on the affected devices. This vulnerability resides within the web interface of the router's administration system, where insufficient input validation allows maliciously crafted parameters to be interpreted and executed as system commands. The flaw specifically manifests in the handling of user-supplied data within the device's web management interface, creating a pathway for privilege escalation and remote code execution. According to CWE-77, this vulnerability falls under the category of command injection, where untrusted data is incorporated into system command calls without proper sanitization or validation. The affected device operates on a Linux-based embedded system where the web server processes user inputs through HTTP requests, making it susceptible to exploitation by authenticated users who possess valid login credentials.
The technical implementation of this vulnerability exploits the router's failure to properly sanitize input parameters submitted through the web interface, particularly within the configuration management functions. When an authenticated user submits specific parameters to the router's web management interface, the system processes these inputs without adequate validation, allowing command injection payloads to be executed with the privileges of the web server process. The vulnerability is classified as a CWE-77 command injection issue that operates at the application layer, where user-supplied data flows directly into system command execution contexts. Attackers can leverage this flaw to execute arbitrary system commands, potentially gaining full control over the router's functionality and accessing sensitive network configurations. The exploitation process typically involves crafting malicious HTTP requests with specially formatted parameters that bypass normal input validation mechanisms, leading to unauthorized command execution on the underlying operating system. This vulnerability directly impacts the router's security model by undermining the principle of least privilege, as authenticated users can escalate their privileges beyond the intended scope of their access rights.
The operational impact of CVE-2018-21106 extends beyond simple command execution, as it enables attackers to compromise the entire network infrastructure managed by the affected router. Once exploited, the vulnerability allows for complete system compromise, enabling attackers to modify router configurations, install malicious software, redirect network traffic, or establish persistence mechanisms within the network. The vulnerability affects the router's ability to maintain network security boundaries, as it provides unauthorized access to the device's core functionalities and potentially exposes the entire network to further attacks. Network administrators face significant risks when this vulnerability remains unpatched, as attackers can use the compromised router as a pivot point for reconnaissance and lateral movement within the network. The impact is particularly severe because the R7800 model is commonly deployed in enterprise and residential environments, making it a valuable target for attackers seeking to gain unauthorized access to network resources. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1068 (Exploitation for Privilege Escalation) techniques, demonstrating how authenticated command injection can be leveraged for broader attack objectives.
Mitigation strategies for CVE-2018-21106 require immediate firmware updates to version 1.0.2.60 or later, which address the input validation flaws that enable command injection. Network administrators should implement strict access controls and monitor network traffic for suspicious activity that may indicate exploitation attempts. The recommended security measures include disabling unnecessary services, implementing network segmentation, and conducting regular vulnerability assessments to identify similar flaws in other network devices. Organizations should also establish robust patch management procedures to ensure timely deployment of security updates across all network infrastructure components. Additional defensive measures include implementing network monitoring solutions that can detect anomalous command execution patterns and configuring intrusion detection systems to flag suspicious HTTP requests. The vulnerability highlights the importance of secure coding practices and input validation in embedded systems, emphasizing the need for thorough security testing during the development lifecycle. Organizations should also consider implementing multi-factor authentication and privileged access management solutions to reduce the attack surface and limit the potential impact of such vulnerabilities. Regular security audits and penetration testing of network infrastructure can help identify similar command injection vulnerabilities in other devices that may be subject to similar exploitation vectors.