CVE-2019-20702 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 • 05/27/2024
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 exists within the web interface authentication mechanism of specific NETGEAR router models including the D3600, D6000, and XR500 series. The affected firmware versions demonstrate a failure in proper input validation and sanitization of user-supplied data, specifically within the parameter handling of web requests. This flaw enables an attacker who has already established authentication credentials to inject malicious commands that are then executed with the privileges of the web server process, typically running with administrative privileges on the device. The vulnerability is particularly concerning because it requires only authentication credentials rather than physical access or advanced exploitation techniques, making it accessible to attackers who have obtained legitimate user credentials through various means such as credential theft, social engineering, or compromised accounts.
The technical implementation of this vulnerability stems from improper handling of user input within the device's web management interface. When authenticated users submit commands or parameters through the web interface, the system fails to properly validate or sanitize these inputs before processing them within the system shell or command execution contexts. This allows attackers to inject malicious command sequences that bypass normal input validation checks and are subsequently executed by the underlying operating system. The vulnerability maps directly to CWE-77, which describes command injection flaws where untrusted data is passed to system commands without proper sanitization. The attack vector involves sending specially crafted HTTP requests containing malicious command payloads through the authenticated web interface, which are then interpreted and executed by the device's command processing subsystem.
The operational impact of this vulnerability extends beyond simple unauthorized command execution, as it provides attackers with persistent access to network infrastructure and potentially enables further lateral movement within the network. Once exploited, attackers can gain complete control over the affected devices, allowing them to modify network configurations, redirect traffic, disable security features, or establish persistent backdoors. The vulnerability affects devices that are commonly deployed in residential and small business environments, where network administrators may not have robust monitoring or detection capabilities in place. This creates a significant risk for organizations that rely on these devices for network connectivity, as they may not be aware of the compromise until significant damage has occurred. The attack surface is particularly broad since these devices often serve as the primary gateway for network traffic and may be running with elevated privileges that allow modification of critical network settings.
Mitigation strategies for this vulnerability require immediate firmware updates from NETGEAR to address the command injection flaw in affected device models. Organizations should prioritize updating all affected D3600, D6000, and XR500 devices to firmware versions 1.0.0.76 or later, which contain the necessary patches to prevent command injection attacks. Network administrators should also implement additional security controls such as restricting access to device management interfaces through firewall rules, limiting authentication credentials to only necessary personnel, and monitoring for suspicious network traffic patterns that may indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.001 for command and script injection, and T1068 for exploit for privilege escalation, making it a significant concern for network security teams. Additionally, implementing network segmentation, regular security assessments, and maintaining up-to-date threat intelligence on known vulnerabilities in network infrastructure helps reduce the overall risk exposure. Organizations should also consider implementing network monitoring solutions that can detect anomalous command execution patterns or unusual traffic flows that may indicate exploitation of this vulnerability.