CVE-2018-21164 in R6220
Summary
by MITRE
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects R6220 before 1.1.0.64 and WNDR3700v5 before 1.1.0.54.
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Analysis
by VulDB Data Team • 10/12/2020
This vulnerability represents a critical command injection flaw in NETGEAR networking equipment that allows authenticated attackers to execute arbitrary commands on affected devices. The issue specifically impacts R6220 routers and WNDR3700v5 wireless routers, with vulnerable versions prior to 1.1.0.64 and 1.1.0.54 respectively. The vulnerability stems from insufficient input validation and sanitization within the device's web interface, which processes user-supplied parameters without proper escaping or filtering mechanisms. When authenticated users submit malicious input through web forms or API endpoints, the system fails to properly validate the data before incorporating it into system commands, creating an avenue for arbitrary code execution. This type of vulnerability falls under CWE-77 and CWE-94 categories, representing command injection and code injection flaws that enable attackers to execute system commands with the privileges of the web server process.
The operational impact of this vulnerability extends beyond simple unauthorized command execution, as it provides attackers with persistent access to the network infrastructure. Once exploited, authenticated users can gain full control over device configuration, modify network settings, redirect traffic, or establish backdoor access points. The affected devices typically operate with elevated privileges, meaning successful exploitation could allow attackers to compromise the entire network segment. This vulnerability aligns with ATT&CK technique T1059.001 for command and script interpreters, where adversaries leverage legitimate system tools to execute malicious commands. The attack surface is particularly concerning given that these devices are often deployed in residential and small business environments where network security awareness may be limited, making the exploitation process more straightforward for adversaries. Network reconnaissance activities can reveal the presence of vulnerable devices, and the authentication requirement does not necessarily prevent exploitation in cases where credentials are compromised through phishing or other means.
Mitigation strategies should prioritize immediate firmware updates from NETGEAR to address the specific command injection flaws in affected device models. Organizations should implement network segmentation to limit access to these devices and restrict administrative access to only trusted users with valid credentials. Regular network monitoring should include detection of unusual command execution patterns or unauthorized configuration changes that might indicate exploitation attempts. The vulnerability demonstrates the importance of input validation and proper sanitization of user-supplied data, as highlighted in industry best practices such as those outlined in the OWASP Top Ten and NIST Cybersecurity Framework. Network administrators should also consider implementing intrusion detection systems that can identify potential exploitation attempts through anomalous command execution patterns, and maintain comprehensive backup configurations to facilitate rapid recovery in case of successful compromise. Additionally, regular security assessments of network infrastructure should include vulnerability scanning for similar command injection flaws in other network equipment to prevent similar issues across the entire network perimeter.