CVE-2019-20732 in D6220
Summary
by MITRE
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects D6220 before 1.0.0.40, D7000v2 before 1.0.0.74, D8500 before 1.0.3.39, DGN2200v4 before 1.0.0.102, DGND2200Bv4 before 1.0.0.102, EX3700 before 1.0.0.70, EX3800 before 1.0.0.70, EX6000 before 1.0.0.30, EX6100 before 1.0.2.22, EX6120 before 1.0.0.40, EX6130 before 1.0.0.22, EX6150v1 before 1.0.0.42, EX6200 before 1.0.3.88, EX7000 before 1.0.0.66, R6250 before 1.0.4.20, R6300v2 before 1.0.4.24, R6400 before 1.0.1.32, R6400v2 before 1.0.2.44, R6700 before 1.0.1.46, R6900 before 1.0.1.46, R7000 before 1.0.9.26, R6900P before 1.3.0.20, R7000P before 1.3.0.20, R7100LG before 1.0.0.40, R7300DST before 1.0.0.62, R7900 before 1.0.2.10, R8000 before 1.0.4.12, R7900P before 1.3.0.10, R8000P before 1.3.0.10, R8300 before 1.0.2.106, R8500 before 1.0.2.106, WN2500RPv2 before 1.0.1.54, WNDR3400v3 before 1.0.1.18, and WNR3500Lv2 before 1.2.0.48.
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Analysis
by VulDB Data Team • 05/31/2024
This vulnerability represents a critical command injection flaw in NETGEAR router firmware 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 mechanism, creating a path for privilege escalation through crafted malicious requests. The vulnerability affects a broad range of NETGEAR wireless routers and gateways spanning multiple product lines including the D-series, EX-series, R-series, and WNR-series devices. Security researchers identified that the flaw exists in the handling of user-supplied parameters within the device management interface, specifically when processing certain HTTP requests that are not properly sanitized before being passed to underlying system commands.
The technical implementation of this vulnerability falls under CWE-77, which describes command injection flaws where untrusted data is incorporated into system commands without proper validation or escaping. Attackers who have gained access to the device through legitimate authentication can exploit this weakness to execute arbitrary shell commands with the privileges of the web server process, typically root or administrative level access. The impact is particularly severe because it allows for complete device compromise, enabling attackers to modify network configurations, install malicious software, redirect traffic, or establish persistent backdoors. This vulnerability directly maps to ATT&CK technique T1059.001 for command and scripting interpreter, and T1068 for exploit for privilege escalation.
Operational exploitation of this vulnerability can lead to significant network security implications, as compromised routers can serve as entry points for broader network infiltration or as command and control nodes for distributed attacks. The affected devices often serve as primary network gateways for residential and small office environments, making them attractive targets for cybercriminals seeking to establish persistent access to local networks. The vulnerability's persistence across multiple firmware versions suggests a fundamental design flaw in the authentication and input handling mechanisms rather than a simple patchable issue. Organizations relying on these devices for network security may find their perimeter defenses compromised, as the vulnerability allows attackers to bypass standard network segmentation and access internal resources. The attack surface extends beyond simple command execution to include potential data exfiltration, network reconnaissance, and the ability to modify firewall rules or DNS settings.
Mitigation strategies should prioritize immediate firmware updates from NETGEAR to address the identified command injection vulnerability, with particular attention to the affected device models and their respective version numbers. Network administrators should implement strict access controls and monitor for unusual network behavior or unauthorized access attempts that might indicate exploitation. The implementation of network segmentation and firewall rules can help limit the potential impact if a device is compromised, while regular security audits should verify that all affected devices have been properly updated. Additionally, organizations should consider disabling unnecessary web management interfaces and implementing multi-factor authentication where possible. The vulnerability highlights the importance of secure coding practices in embedded systems and the need for regular security assessments of network infrastructure devices, particularly those with web-based management interfaces that handle user input without proper sanitization.