CVE-2026-105484 in X6000R
Summary
by MITRE • 10/06/2026
A security vulnerability has been detected in TOTOLINK X6000R 9.4.0cu.652_B20230116. The impacted element is the function firmware_check of the file /cgi-bin/cstecgi.cgi of the component UploadFirmwareFile Handler. Such manipulation of the argument file_name leads to os command injection. The attack may be performed from remote.
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified in TOTOLINK X6000R firmware version 9.4.0cu.652_B20230116 represents a critical security flaw within the device's web management interface, specifically located in the UploadFirmwareFile handler component. This issue resides within the cgi-bin/cstecgi.cgi script, which serves as the primary gateway for administrative interactions with the router’s firmware subsystem. The core of the problem lies in the improper validation and sanitization of input data passed to the firmware_check function. When a user or attacker submits a request containing a file_name argument, the system fails to adequately strip or escape special characters that hold significance to the underlying operating system shell. This lack of rigorous input filtering allows an adversary to inject arbitrary command-line instructions directly into the execution context of the device’s backend processes.
From a technical perspective, this flaw is classified as OS Command Injection, which aligns with CWE-78 in the Common Weakness Enumeration taxonomy. The vulnerability arises because the application constructs system commands by concatenating user-supplied input without sufficient sanitization. In typical embedded Linux environments used by routers like the TOTOLINK X6000R, such injections can leverage standard shell metacharacters to terminate the intended command and append new ones. For instance, an attacker could supply a file name ending with a semicolon or pipe character followed by malicious commands. Because this function is part of the firmware update mechanism, it often executes with elevated privileges necessary for writing files to system partitions or triggering reboots. Consequently, successful exploitation allows for arbitrary code execution on the target device’s operating system kernel level, bypassing standard application-level security controls entirely.
The operational impact of this vulnerability is severe due to its remote exploitability and high privilege context. An attacker does not need physical access to the router nor do they require prior authentication if the web interface permits unauthenticated access to certain endpoints or if session hijacking techniques are employed, although typically firmware upload functions may require administrative credentials. However, even with authenticated access, this vulnerability enables complete compromise of the network infrastructure. Once an attacker achieves command execution on the router, they can pivot into the internal local area network, intercepting sensitive traffic, modifying DNS settings to facilitate phishing or man-in-the-middle attacks, and installing persistent backdoors for long-term surveillance. The ability to execute commands remotely makes this a high-risk vector that could lead to widespread data breaches if left unpatched in enterprise or residential environments where such routers are commonly deployed as gateways.
This vulnerability maps directly to the MITRE ATT&CK framework under techniques related to Command and Scripting Interpreter abuse, specifically T1059, which covers execution of commands via system utilities available on the target platform. The attack vector is classified as Network-based with Remote Prerequisites, falling under TA0002 Execution in the tactical phase mapping. To mitigate this risk, immediate action must be taken to update the TOTOLINK X6000R firmware to a version that addresses this input validation flaw. If an official patch is not yet available, network segmentation strategies should be employed to restrict access to the router’s management interface solely from trusted internal subnets or through secure VPN tunnels rather than exposing it directly to untrusted networks like the internet. Additionally, implementing strict firewall rules to block outbound connections from compromised devices can limit lateral movement and data exfiltration capabilities in the event of a successful exploitation attempt until remediation is complete.