CVE-2019-20689 in D6000
Summary
by MITRE
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects D6000 before 1.0.0.75, D6100 before 1.0.0.63, EX2700 before 1.0.1.48, EX6100v2 before 1.0.1.76, EX6150v2 before 1.0.1.76, EX6200v2 before 1.0.1.72, EX6400 before 1.0.2.136, EX7300 before 1.0.2.136, EX8000 before 1.0.1.180, R7800 before 1.0.2.52, R8900 before 1.0.4.2, R9000 before 1.0.4.2, WN2000RPTv3 before 1.0.1.32, WN3000RPv2 before 1.0.0.68, WN3100RPv2 before 1.0.0.60, WNDR3700v4 before 1.0.2.102, WNDR4300v1 before 1.0.2.104, WNDR4300v2 before 1.0.0.58, WNDR4500v3 before 1.0.0.58, WNR2000v5 before 1.0.0.68, 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 users to execute arbitrary commands on affected devices. The issue stems from insufficient input validation and sanitization within the device's web interface handling mechanisms, specifically affecting a wide range of consumer and small office routers and access points. The vulnerability exists in the device's processing of user-supplied input through web forms and API endpoints, where maliciously crafted parameters can be interpreted as shell commands rather than simple data inputs. This authentication requirement means that an attacker must first establish valid credentials to exploit the vulnerability, but once achieved, the impact extends to full device compromise and potential network infiltration.
The technical implementation of this flaw involves the improper handling of user-controllable data within the device's command execution pipeline. When legitimate users submit forms through the web interface, the application fails to properly sanitize or escape input parameters before using them in system calls or shell commands. This creates an environment where crafted input can be interpreted by the underlying operating system as actual commands to execute, enabling attackers to gain unauthorized access to the device's command shell and execute arbitrary code with the privileges of the web server process. The vulnerability affects multiple device models across different product lines, suggesting a systemic issue in the software development practices rather than isolated implementation errors. According to CWE-77, this maps directly to command injection vulnerabilities where untrusted data is used in command execution contexts without proper validation or sanitization.
The operational impact of this vulnerability extends far beyond simple device compromise, as authenticated command injection allows attackers to manipulate network configurations, redirect traffic, install malware, or use the device as a pivot point for attacking other systems within the local network. Attackers could potentially modify firewall rules, change administrator credentials, install backdoors, or even use the compromised device to launch further attacks against external networks. The affected devices include popular consumer-grade routers and access points that typically serve as gateways between home networks and the internet, making them attractive targets for attackers seeking persistent network access. The vulnerability affects devices from 2015 through 2019 model years, indicating a long-standing issue in the vendor's software development lifecycle that was not adequately addressed through security reviews or testing. This vulnerability aligns with ATT&CK technique T1059.001 for command and script injection, and T1068 for exploit for privilege escalation.
Organizations and individuals should immediately implement several mitigation strategies to protect against exploitation of this vulnerability. The primary recommendation involves updating all affected devices to the latest firmware versions provided by NETGEAR, as these releases contain patches that properly sanitize input parameters and prevent command injection attacks. Network segmentation and monitoring should be implemented to detect unusual network traffic patterns that might indicate exploitation attempts, particularly focusing on traffic originating from compromised devices. Access controls should be strengthened through the use of strong, unique passwords and multi-factor authentication where available, as the vulnerability requires authentication to exploit. Regular network scanning and vulnerability assessments should be conducted to identify any remaining unpatched devices within the network infrastructure. Additionally, implementing network intrusion detection systems can help identify and alert on suspicious command execution patterns that may indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and secure coding practices, particularly in network infrastructure devices that handle user input through web interfaces and API endpoints.