CVE-2026-75984 in TEW-823DRU
Summary
by MITRE • 08/19/2026
A vulnerability was detected in TRENDnet TEW-823DRU 1.1.02b01. Impacted is an unknown function of the file /cgi-bin/admin.cgi. The manipulation of the argument Hostname results in command injection. The attack can be launched remotely. The exploit is now public and may be used.
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Analysis
by VulDB Data Team • 08/19/2026
The TRENDnet TEW-823DRU wireless router, specifically running firmware version 1.1.02b01, contains a critical security flaw within its web-based management interface that allows for remote command injection. This vulnerability resides in the admin.cgi script located at /cgi-bin/admin.cgi and is triggered by improper validation of input provided to the Hostname argument. The presence of this flaw indicates a fundamental failure in implementing secure coding practices during the development of the router's embedded Linux environment, where user-supplied data was directly concatenated into system commands without adequate sanitization or escaping mechanisms.
From a technical perspective, the vulnerability is classified under CWE-78, which denotes Improper Neutralization of Special Elements used in an OS Command (OS Command Injection). The attacker can exploit this by crafting a malicious HTTP request that includes specially formatted strings within the Hostname parameter. These strings typically include shell metacharacters such as semicolons or ampersands, which allow the injection of arbitrary operating system commands into the execution context of the admin.cgi script. Because the CGI process often runs with elevated privileges to manage network settings and firmware updates, successfully exploiting this flaw grants the attacker a high-level command shell on the device.
The operational impact of this vulnerability is severe due to its remote nature and public availability. Since the attack can be launched remotely over the internet without requiring authentication in many default configurations or even when weak credentials are used, it poses an immediate threat to network integrity. An adversary who exploits this flaw gains full control over the compromised router. This level of access allows for a wide range of malicious activities including intercepting and modifying unencrypted traffic, redirecting users to phishing sites via DNS manipulation, installing persistent malware or botnet agents on the device, and using the router as a pivot point to attack other devices within the local network segment. The fact that an exploit is publicly available significantly lowers the barrier for entry, enabling automated scanning tools and less sophisticated attackers to compromise vulnerable systems at scale.
This vulnerability aligns with several tactics in the MITRE ATT&CK framework, particularly Initial Access techniques involving exploitation of remote services and Execution techniques related to command-line interface abuse. The lack of input validation represents a classic example of CWE-20 Improper Input Validation, which is often cited as a root cause for injection flaws across various software domains.
To mitigate this risk, immediate action is required from administrators using the affected hardware. The primary remediation step is to update the router firmware to the latest version released by TRENDnet, provided that a patch has been issued addressing this specific command injection flaw in the admin.cgi script. If an official patch is unavailable or if the device is no longer supported, it is strongly recommended to replace the hardware with a model from a vendor that maintains a robust security update lifecycle and adheres to secure development standards such as OWASP Top Ten guidelines for web applications. Additionally, until mitigation can be applied, administrators should ensure that remote management features are disabled in the router settings, restrict access to the administrative interface to trusted local IP addresses only, and change default credentials to strong, unique passwords to reduce the attack surface even if other vulnerabilities exist.