CVE-2026-6989 in F453
Summary
by MITRE • 04/25/2026
A vulnerability has been found in Tenda F453 up to 1.0.0.3. Impacted is the function TendaTelnet of the file /goform/telnet of the component Telnet Service. Such manipulation leads to command injection. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 06/04/2026
The vulnerability identified in Tenda F453 router firmware version 1.0.0.3 represents a critical command injection flaw within the telnet service component. This issue resides in the TendaTelnet function located at /goform/telnet within the Telnet Service module, exposing the device to remote exploitation. The vulnerability allows attackers to execute arbitrary commands on the affected device through remote manipulation of the telnet service interface. Security researchers have confirmed that a public exploit exists for this vulnerability, making it immediately actionable by threat actors without requiring advanced technical skills or specialized tools. The presence of a disclosed exploit significantly elevates the risk profile of this vulnerability, as it removes the barrier between discovery and exploitation, enabling widespread compromise of affected devices.
The technical nature of this vulnerability can be classified as a command injection flaw, which falls under CWE-77 and CWE-94 in the Common Weakness Enumeration catalog. This type of vulnerability occurs when user-supplied input is directly incorporated into system commands without proper sanitization or validation. The flaw specifically affects the telnet service component where the TendaTelnet function fails to properly validate or sanitize input parameters before executing system commands. This allows attackers to inject malicious commands that are then executed with the privileges of the telnet service process. The vulnerability's remote exploitability means that attackers do not require physical access or local network presence to compromise the device, as the attack can be launched from any location with network connectivity to the affected router.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass complete system compromise of affected Tenda F453 devices. An attacker who successfully exploits this vulnerability gains the ability to execute arbitrary commands on the router, potentially leading to full system control including the ability to modify router configurations, establish persistent backdoors, access network traffic, or use the compromised device as a launching point for attacks against other networked systems. The telnet service, when enabled, provides an additional attack surface that can be leveraged for lateral movement within networks, particularly in environments where routers serve as network gateways. This vulnerability essentially transforms the affected router into a potential command and control node for broader network attacks, making it a significant concern for both individual users and enterprise network security.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from Tenda, as the manufacturer has likely released patches to address this specific command injection flaw. Network administrators should disable the telnet service entirely if it is not required for legitimate operations, as this removes the attack surface entirely. Additional protective measures include implementing network segmentation to isolate affected devices, monitoring network traffic for suspicious command execution patterns, and deploying intrusion detection systems that can identify exploitation attempts. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1021.001 (Remote Services: Remote Desktop Protocol) through the command execution capabilities it provides. Organizations should also consider implementing network access controls to restrict access to the telnet service port and regularly audit router configurations to ensure that unnecessary services remain disabled. Given the public availability of exploit code, immediate remediation is essential to prevent exploitation and maintain network security posture.