CVE-2018-21154 in D7800
Summary
by MITRE
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects D7800 before 1.0.1.34, DM200 before 1.0.0.50, R6100 before 1.0.1.22, R7500 before 1.0.0.122, R7500v2 before 1.0.3.26, and R7800 before 1.0.2.42.
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Analysis
by VulDB Data Team • 06/03/2024
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 web interface authentication handling mechanisms, creating a pathway for privilege escalation and remote code execution. The vulnerability affects multiple router models including the D7800, DM200, R6100, R7500, R7500v2, and R7800, all of which have specific firmware versions that remain vulnerable. The authentication requirement means that an attacker must first obtain valid credentials, but once authenticated, they can leverage this flaw to gain unauthorized control over the device's operating system functions.
The technical exploitation of this vulnerability occurs through improper handling of user-supplied input within the device's web management interface. When authenticated users submit certain parameters to specific API endpoints or form fields, the system fails to properly sanitize these inputs before processing them within the command execution context. This creates an environment where maliciously crafted input can be interpreted and executed as shell commands, effectively allowing attackers to bypass normal access controls and execute arbitrary code with the privileges of the authenticated user. The vulnerability is classified under CWE-77 as "Command Injection," which is a well-documented weakness that has been consistently exploited in network infrastructure devices. The flaw operates at the application layer, specifically within the web server component that handles user authentication and device management requests.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass complete device compromise and potential network infiltration. An authenticated attacker could leverage this flaw to modify device configurations, install malicious firmware, redirect network traffic, or use the compromised device as a pivot point for attacking other systems within the network. The vulnerability also poses significant risks to network security posture as it enables attackers to potentially establish persistent access to network infrastructure. Additionally, the affected devices may be used to conduct further reconnaissance activities or serve as command and control nodes for larger attack campaigns, making this vulnerability particularly dangerous in enterprise environments where network devices serve as critical infrastructure components.
Mitigation strategies for this vulnerability should include immediate firmware updates from NETGEAR to address the command injection flaw, along with network segmentation to limit the potential impact of successful exploitation. Organizations should implement robust access control measures, including strong authentication mechanisms, regular credential rotation, and monitoring for unusual network activity that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and the principle of least privilege in network device management, aligning with ATT&CK technique T1059.001 for Command and Scripting Interpreter. Security teams should also consider implementing network monitoring solutions that can detect anomalous command execution patterns and ensure that all network infrastructure devices are regularly assessed for similar vulnerabilities through vulnerability scanning and penetration testing activities.