CVE-2018-21107 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-2018-21107 affects NETGEAR R7800 wireless routers running firmware versions prior to 1.0.2.60. This represents a critical command injection flaw that allows authenticated users to execute arbitrary commands on the affected device. The vulnerability stems from insufficient input validation and sanitization within the router's web interface, specifically in the handling of user-supplied parameters that are subsequently passed to system commands without proper escaping or filtering. The affected device operates on a Linux-based embedded system where the web server component processes user inputs directly into shell commands, creating a direct pathway for malicious command execution.
This vulnerability falls under the Common Weakness Enumeration category CWE-77, which specifically addresses command injection flaws in software systems. The attack vector requires an authenticated user with access to the router's administrative interface, typically through valid credentials for the web management portal. Once authenticated, an attacker can manipulate parameters in HTTP requests sent to the router's web server, particularly in forms or API endpoints that handle network configuration settings. The lack of proper input sanitization allows malicious payloads to be executed with the privileges of the web server process, which typically runs with elevated permissions on the router's embedded system. This creates a significant risk as the compromised device can be used to execute arbitrary code, potentially leading to complete system compromise, data exfiltration, or further network infiltration.
The operational impact of this vulnerability extends beyond simple command execution, as it can enable attackers to modify network configurations, establish persistent backdoors, or use the compromised router as a pivot point for attacking other devices within the local network. The vulnerability affects the router's ability to maintain network security boundaries, as an authenticated attacker can manipulate the device's routing tables, DNS settings, or firewall rules. Additionally, the compromised device may be used to launch attacks against external systems or serve as a command and control node for botnet activities. The embedded nature of the device and its typical deployment in home or small office environments means that the impact can be severe, as these devices often serve as the primary gateway to the internet for multiple devices and may lack proper network segmentation or monitoring.
Mitigation strategies for CVE-2018-21107 primarily focus on firmware updates, which NETGEAR has addressed through the release of version 1.0.2.60 and subsequent releases. Organizations and individuals should immediately upgrade to the latest firmware version available from NETGEAR's official website, ensuring that the update process is performed through secure channels to prevent supply chain attacks. Network administrators should also implement additional security measures including regular firmware audits, monitoring for unauthorized access attempts, and network segmentation to limit the potential impact of a compromised device. The vulnerability demonstrates the importance of input validation and proper parameter handling in embedded systems, aligning with ATT&CK technique T1059 for command and script injection. Security professionals should also consider implementing network monitoring solutions that can detect anomalous command execution patterns or unusual network traffic originating from compromised devices, as these may indicate exploitation of similar vulnerabilities.