CVE-2018-21098 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 • 06/03/2024
The vulnerability identified as CVE-2018-21098 affects NETGEAR R7800 wireless routers running firmware versions prior to 1.0.2.60, representing a critical command injection flaw that allows authenticated users to execute arbitrary commands on the affected device. This vulnerability resides within the web interface of the router's management system, specifically in how the device processes user-supplied input parameters. The flaw stems from inadequate input validation and sanitization mechanisms that fail to properly escape or filter command characters and sequences, enabling maliciously crafted input to be interpreted and executed as shell commands by the underlying operating system. The vulnerability is classified under CWE-77 as "Command Injection" which is a well-documented weakness in software applications that execute system commands based on user input without proper validation.
The operational impact of this vulnerability is severe and multifaceted, as it provides an authenticated attacker with complete control over the affected router's functionality. Once exploited, the attacker can execute arbitrary commands with the privileges of the web server process, which typically runs with elevated permissions on the device. This allows for complete compromise of the router's configuration, enabling actions such as modifying network settings, creating backdoor access points, redirecting traffic, disabling security features, or even installing persistent malware on the device. The vulnerability can be leveraged to establish a persistent foothold within the network, as the compromised router can serve as a pivot point for further attacks against internal network resources. From an attack perspective, this vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, specifically targeting the command shell component of the affected device.
The technical exploitation of this vulnerability requires an authenticated user session with administrative privileges, which significantly reduces the attack surface but does not eliminate the risk entirely. Network administrators who have configured default credentials or failed to implement proper access controls may inadvertently provide attackers with the necessary authentication credentials. The vulnerability is particularly concerning because it allows for privilege escalation and persistent access, making it a preferred target for attackers seeking long-term network infiltration. Organizations should note that this vulnerability represents a classic example of insufficient input validation in web applications, where user-provided data flows directly into system command execution contexts without proper sanitization or escaping mechanisms.
Mitigation strategies for CVE-2018-21098 should focus on immediate firmware updates to version 1.0.2.60 or later, which contain the necessary patches to address the command injection vulnerability. Network administrators should also implement strict access controls and authentication policies, ensuring that only authorized personnel have administrative access to router configurations. Additional security measures include disabling unnecessary services, implementing network segmentation, and monitoring for unusual network behavior that might indicate exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other network infrastructure devices. The vulnerability serves as a reminder of the critical importance of input validation and proper sanitization in web applications, as well as the necessity of keeping network device firmware up to date to protect against known security flaws. Organizations should also consider implementing network monitoring solutions that can detect anomalous command execution patterns or unauthorized configuration changes that might indicate successful exploitation of similar vulnerabilities.