CVE-2021-45614 in D7000v2
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects D7000v2 before 1.0.0.74, LAX20 before 1.1.6.28, MK62 before 1.0.6.116, MR60 before 1.0.6.116, MS60 before 1.0.6.116, RAX15 before 1.0.3.96, RAX20 before 1.0.3.96, RAX200 before 1.0.4.120, RAX45 before 1.0.3.96, RAX50 before 1.0.3.96, RAX43 before 1.0.3.96, RAX40v2 before 1.0.3.96, RAX35v2 before 1.0.3.96, RAX75 before 1.0.4.120, RAX80 before 1.0.4.120, RBK752 before 3.2.17.12, RBR750 before 3.2.17.12, RBS750 before 3.2.17.12, RBK852 before 3.2.17.12, RBR850 before 3.2.17.12, RBS850 before 3.2.17.12, and XR1000 before 1.0.0.58.
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Analysis
by VulDB Data Team • 12/28/2021
This vulnerability represents a critical command injection flaw in NETGEAR networking equipment that allows unauthenticated attackers to execute arbitrary commands on affected devices. The issue stems from improper input validation within the device's web interface handling, specifically in the processing of user-supplied parameters that are directly incorporated into system commands without adequate sanitization. This vulnerability affects a broad range of consumer and small office networking devices including routers, access points, and mesh systems, with the affected versions spanning multiple product lines from the D7000v2 series through various RAX and RBK models. The flaw resides in the device's web server implementation where user-provided data is concatenated into shell commands, creating an environment where malicious input can be interpreted as executable commands by the underlying operating system. The vulnerability is classified as a command injection weakness under CWE-77, which is a well-documented software security flaw that allows attackers to execute arbitrary commands on the target system. The attack vector is particularly concerning because it requires no authentication, making it accessible to anyone who can reach the device's web interface, which is often exposed to the internet in home and small office environments. The impact extends beyond simple command execution to potentially allow full device compromise, including the ability to modify device configuration, install malicious firmware, or establish persistent backdoors. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1059.001 for command and script injection, and T1021.001 for remote services. The affected devices typically run embedded operating systems with limited security controls, making them particularly susceptible to exploitation. The vulnerability affects devices that are commonly deployed in unsecured environments where network segmentation is minimal or absent, increasing the attack surface for potential exploitation. Network administrators and security professionals should note that these devices often serve as entry points for broader network infiltration attacks, as they are frequently located in the demilitarized zone between internal networks and the internet.
The technical implementation of this vulnerability involves the improper handling of user input within the device's web application layer. When an attacker sends specially crafted requests to the device's web interface, the application fails to properly validate or sanitize the input parameters before using them in system commands. This typically occurs in CGI scripts or web server modules where user input is directly concatenated into command strings without appropriate escaping or filtering mechanisms. The affected devices use embedded Linux-based operating systems with standard web servers such as lighttpd or similar implementations that are vulnerable to this type of injection attack. Attackers can leverage this vulnerability by crafting HTTP requests with malicious command payloads that, when processed by the vulnerable web application, are executed with the privileges of the web server process. This often translates to root-level access on the device, allowing for complete compromise of the networking equipment. The exploitation process typically involves sending HTTP requests with specially crafted parameters that bypass normal input validation and directly inject shell commands into the system. The vulnerability affects multiple firmware versions across various product lines, indicating a systemic issue in the codebase rather than isolated instances, suggesting that the root cause likely exists in shared components or common development practices across the affected device families.
The operational impact of this vulnerability is severe and multifaceted for organizations and individual users. Device compromise can lead to complete network infiltration, as these devices often serve as gateways between internal networks and external internet access. An attacker who successfully exploits this vulnerability can gain persistent access to the device, potentially using it as a pivot point for attacking other systems within the local network. The compromised device may be used to conduct man-in-the-middle attacks, redirect traffic, or serve as a command and control node for botnet activities. Additionally, the vulnerability can result in denial of service conditions if attackers choose to execute commands that disrupt device functionality or consume system resources. The affected device families include both consumer-grade and small business networking equipment, which are often deployed without proper security hardening or network monitoring. The lack of authentication requirements makes this vulnerability particularly dangerous as it can be exploited from any location with internet connectivity, without requiring local access or credentials. Organizations that have not updated their device firmware may be unknowingly running vulnerable equipment, creating persistent security risks in their network infrastructure. The vulnerability also impacts the integrity and availability of network services, as compromised devices may fail to properly route traffic or maintain their intended functionality. Security researchers have noted that these devices often lack proper logging mechanisms, making it difficult to detect exploitation attempts or determine the full scope of compromise after an attack has occurred. The widespread nature of affected devices means that many organizations may be running vulnerable equipment without awareness, creating a significant security exposure in the broader internet ecosystem.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from NETGEAR, which have been released to address the command injection flaw. Organizations should prioritize updating all affected devices to the latest firmware versions, as these releases include proper input validation and sanitization mechanisms to prevent the injection of malicious commands. Network segmentation should be implemented to limit the exposure of these devices to internal networks, using firewalls and access control lists to restrict communication between the vulnerable devices and sensitive internal systems. Monitoring network traffic for suspicious activity related to these specific device models can help detect exploitation attempts, particularly looking for unusual HTTP requests or command execution patterns. Device hardening practices should be implemented including disabling unnecessary services, changing default credentials, and restricting remote management access to trusted IP addresses. Network administrators should consider implementing intrusion detection systems that can identify patterns associated with command injection attacks against these specific device types. Regular vulnerability assessments should be conducted to identify any remaining unpatched devices within the network infrastructure. The use of network access control lists and firewall rules can help prevent unauthorized access to the devices from external networks, while internal monitoring can detect attempts to access the devices from within the local network. Organizations should also consider implementing device inventory management to track all networking equipment and ensure that firmware updates are applied consistently across all affected devices. Given the nature of the vulnerability, it is recommended that organizations perform thorough network audits to identify all potentially affected devices, including those that may be running older firmware versions or have been overlooked in previous security assessments. Regular security awareness training for network administrators can help ensure proper device management practices and timely application of security patches. The vulnerability also underscores the importance of maintaining up-to-date security practices for embedded networking equipment, as these devices often receive less attention than traditional computing systems in security monitoring and patch management processes.