CVE-2014-0356 in Wireless N300 NetUSB
Summary
by MITRE
The ZyXEL Wireless N300 NetUSB NBG-419N router with firmware 1.00(BFQ.6)C0 allows remote attackers to execute arbitrary code via shell metacharacters in input to the (1) detectWeather, (2) set_language, (3) SystemCommand, or (4) NTPSyncWithHost function in management.c, or a (5) SET COUNTRY, (6) SET WLAN SSID, (7) SET WLAN CHANNEL, (8) SET WLAN STATUS, or (9) SET WLAN COUNTRY udps command.
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Analysis
by VulDB Data Team • 05/10/2026
The vulnerability identified as CVE-2014-0356 affects the ZyXEL Wireless N300 NetUSB NBG-419N router running firmware version 1.00(BFQ.6)C0, representing a critical remote code execution flaw that enables attackers to gain unauthorized control over the affected device. This vulnerability stems from inadequate input validation within multiple functions of the router's management.c component and udps command handlers, creating multiple attack vectors that can be exploited without authentication. The flaw specifically manifests in the detectWeather, set_language, SystemCommand, and NTPSyncWithHost functions, as well as in the SET COUNTRY, SET WLAN SSID, SET WLAN CHANNEL, SET WLAN STATUS, and SET WLAN COUNTRY udps commands, all of which are susceptible to shell injection attacks through improper sanitization of user-supplied input data.
The technical implementation of this vulnerability involves the router's failure to properly escape or filter special shell metacharacters in user-controllable parameters, allowing attackers to inject malicious commands that are subsequently executed by the underlying shell environment. This represents a classic command injection vulnerability classified under CWE-77, which occurs when a program constructs a command string using externally-influenced input from an upstream component, but does not sufficiently sanitize that input before using it in the command. The attack surface expands significantly due to the multiple entry points, with each vulnerable function providing a separate pathway for exploitation. The router's web management interface and UDP-based commands all present opportunities for attackers to craft malicious payloads that leverage shell metacharacters such as semicolons, pipes, and backticks to execute arbitrary code on the target device.
The operational impact of this vulnerability is severe and far-reaching, as it allows remote attackers to execute arbitrary code with the privileges of the router's system user, potentially leading to complete device compromise. Attackers can leverage this vulnerability to install malware, modify network configurations, redirect traffic, or establish persistent backdoors for future access. The remote nature of the attack means that adversaries do not require physical access to the device, nor do they need valid credentials, making the vulnerability particularly dangerous in network environments where routers are exposed to external traffic. The compromised device can then serve as a launching point for further attacks within the local network, potentially enabling lateral movement and privilege escalation against other connected systems. This vulnerability also affects network availability and integrity, as attackers can manipulate routing decisions, disable security features, or cause service disruption through command injection.
Mitigation strategies for CVE-2014-0356 should prioritize immediate firmware updates from ZyXEL, as the vendor likely released patches addressing this specific vulnerability. Network administrators should implement network segmentation to isolate affected routers from critical systems and enforce strict firewall rules that block unauthorized access to router management interfaces. The principle of least privilege should be applied by restricting access to router management functions to trusted network segments only, while disabling unnecessary services and protocols such as the udps command interface when not required. Additional protective measures include implementing intrusion detection systems to monitor for suspicious traffic patterns, conducting regular vulnerability assessments of network infrastructure, and maintaining up-to-date network configuration baselines. Security monitoring should focus on detecting unusual command execution patterns or unauthorized configuration changes that may indicate exploitation attempts, while also ensuring that all network devices undergo regular security audits and that access controls are properly configured according to established security frameworks such as those outlined in the NIST Cybersecurity Framework and ISO/IEC 27001 standards.