CVE-2019-20726 in D3600
Summary
by MITRE
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects D3600 before 1.0.0.75, D6000 before 1.0.0.75, D6100 before 1.0.0.63, R7800 before 1.0.2.52, R8900 before 1.0.4.2, R9000 before 1.0.4.2, 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 • 05/31/2024
This vulnerability represents a critical command injection flaw in NETGEAR networking equipment that allows authenticated users to execute arbitrary commands on affected devices. The vulnerability exists within the web-based management interface of multiple router models, specifically targeting the command execution mechanisms used for network configuration and system administration tasks. Attackers who have gained legitimate access to the device through valid credentials can leverage this flaw to escalate their privileges and gain full control over the affected network infrastructure. The affected models span several generations of NETGEAR routers including popular R7800, R8900, R9000 series and various D and WNDR models, indicating a widespread impact across the vendor's product portfolio.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the web interface's backend processing functions. When legitimate users submit commands through the administrative interface, the system fails to properly sanitize user-supplied input before executing these commands on the underlying operating system. This creates an environment where maliciously crafted input can be interpreted as system commands rather than simple data, allowing attackers to inject and execute arbitrary code. The vulnerability manifests in the handling of parameters passed to system commands, where user input flows directly into shell execution contexts without proper filtering or escaping mechanisms. This pattern aligns with CWE-77 and CWE-89, which specifically address command injection vulnerabilities and improper neutralization of special elements used in SQL commands, respectively.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete network compromise. Once an attacker gains authenticated access, they can execute system commands that may include network monitoring, data exfiltration, configuration modification, or even installation of persistent backdoors. The affected devices operate as core network infrastructure components, making them attractive targets for attackers seeking long-term access to corporate or residential networks. The vulnerability particularly concerns network administrators because it allows attackers to manipulate routing tables, disable security features, or redirect network traffic through malicious command execution. Additionally, the widespread nature of affected models means that numerous network environments could be compromised simultaneously, potentially affecting hundreds or thousands of devices across different organizations.
Mitigation strategies should focus on immediate firmware updates provided by NETGEAR to address the command injection vulnerability. Organizations must ensure all affected devices receive the latest security patches as released by the vendor, with particular attention to the specific firmware versions mentioned in the vulnerability disclosure. Network segmentation and access control measures should be implemented to limit the scope of potential compromise, ensuring that even if one device is compromised, attackers cannot easily move laterally across the network. Regular security audits of network infrastructure should include verification of device firmware versions and configuration settings to detect unauthorized modifications. The vulnerability demonstrates the importance of implementing principle of least privilege for administrative access and maintaining up-to-date security controls. Organizations should also consider implementing network monitoring solutions that can detect unusual command execution patterns or unauthorized configuration changes that might indicate exploitation of this vulnerability. This issue aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, highlighting the need for comprehensive defensive measures across multiple attack vectors.