CVE-2018-21146 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, R7800 before 1.0.2.42, R8900 before 1.0.3.10, R9000 before 1.0.3.10, WNDR4300v2 before 1.0.0.54, and WNDR4500v3 before 1.0.0.54.
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Analysis
by VulDB Data Team • 06/01/2024
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 stems from insufficient input validation and sanitization within the web interface authentication mechanisms, enabling malicious actors who have already gained access to the device to escalate their privileges and execute system-level commands. The affected models include several popular router series including the D7800, R7800, R8900, R9000, WNDR4300v2, and WNDR4500v3, all of which were released with firmware versions prior to the specified patches. This issue falls under the common weakness enumeration CWE-77 which specifically addresses command injection vulnerabilities where untrusted data is incorporated into system commands without proper validation or escaping mechanisms.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with complete control over the affected networking equipment. Once authenticated, an attacker can leverage this vulnerability to execute arbitrary shell commands, potentially leading to network compromise, data exfiltration, or the establishment of persistent backdoors within the network infrastructure. The vulnerability affects devices that are commonly deployed in both residential and enterprise environments, making it particularly dangerous as it could enable attackers to gain control over critical network access points. The fact that these devices are often located in network perimeters makes them attractive targets for attackers seeking to establish footholds within larger networks or to disrupt network operations.
From a security perspective, this vulnerability demonstrates the importance of implementing proper input validation and sanitization mechanisms within web-based administrative interfaces. The flaw allows authenticated users to inject malicious commands that bypass normal security controls, effectively undermining the authentication mechanism itself. Network administrators should consider this vulnerability in the context of the attack chain described in the MITRE ATT&CK framework where it could represent a privilege escalation technique following initial access through legitimate authentication. The vulnerability's impact is amplified by the fact that many of these devices are configured with default credentials or have weak authentication mechanisms, making them more susceptible to exploitation. Organizations should prioritize patching these devices as soon as possible, as the vulnerability provides a direct path to system compromise without requiring additional attack vectors. The affected firmware versions represent a significant security risk that could enable attackers to perform actions such as modifying network configurations, installing malware, or creating unauthorized network access points that could be used for further attacks.