CVE-2019-20711 in D3600
Summary
by MITRE
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects D3600 before 1.0.0.76, D6000 before 1.0.0.76, and XR500 before 2.3.2.32.
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Analysis
by VulDB Data Team • 05/31/2024
This vulnerability represents a critical command injection flaw in NETGEAR networking equipment that allows authenticated attackers to execute arbitrary commands on affected devices. The vulnerability specifically impacts three device models including the D3600, D6000, and XR500 routers, with affected firmware versions prior to 1.0.0.76 for D3600 and D6000, and prior to 2.3.2.32 for XR500. The flaw stems from insufficient input validation and sanitization within the device's web interface handling, where user-supplied parameters are directly incorporated into system commands without proper escaping or filtering mechanisms. This type of vulnerability falls under CWE-77 which categorizes command injection flaws as weaknesses in software that allows attackers to execute operating system commands through untrusted input. The authenticated nature of this vulnerability means that an attacker must first obtain valid credentials to exploit the flaw, typically through credential guessing, password reuse, or other initial compromise techniques that align with ATT&CK technique T1110 for credential access.
The operational impact of this vulnerability extends beyond simple unauthorized command execution, as it enables attackers to gain complete control over the affected network devices. Once exploited, attackers can modify device configurations, redirect traffic, install malicious firmware, or use the compromised device as a pivot point for further network infiltration. The affected devices operate as core network infrastructure components, making them attractive targets for attackers seeking persistent access to corporate or residential networks. Network traffic passing through these compromised devices becomes vulnerable to interception, modification, or complete redirection, potentially enabling man-in-the-middle attacks and data exfiltration. The vulnerability's presence in consumer-grade networking equipment also means that many organizations may not be aware of these devices on their networks, creating additional attack surface that can be leveraged for lateral movement within networks.
Mitigation strategies should prioritize immediate firmware updates from NETGEAR to address the command injection vulnerability, with particular attention to verifying that the updated firmware versions are properly installed and that the affected devices are no longer accessible to unauthorized users. Network segmentation and access control measures should be implemented to limit the potential impact of compromised devices, including restricting administrative access to only necessary personnel and implementing strong authentication mechanisms. Security monitoring should include detection of unusual network traffic patterns and configuration changes that might indicate exploitation attempts. Additionally, organizations should conduct network discovery scans to identify all instances of affected NETGEAR devices and ensure that default credentials are changed, as these vulnerabilities are often exploited through default credential attacks. The vulnerability demonstrates the importance of input validation and secure coding practices in network infrastructure devices, aligning with security frameworks that emphasize the need for robust sanitization of user inputs and proper command construction to prevent arbitrary code execution.