Description

An issue in Tneda W20E v.16.01.0.6(2782) allows a remote attacker to execute arbitrary code via the url_need_login function

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-08-17T21:16:47.610Z",
  "pubdate": "2026-08-17T21:16:47.610Z",
  "executiveSummary": "An arbitrary code execution vulnerability has been identified in the Tenda W20E router running firmware version v.16.01.0.6(2782). The flaw resides within the internal handling logic of the url_need_login function.\nThis vulnerability allows an unauthenticated remote attacker to execute arbitrary system commands on the underlying operating system by interacting with the exposed web interface.\nSuccessful exploitation of this issue can lead to complete compromise of the affected routing device, granting the adversary full administrative control over the hardware, network traffic interception capabilities, and a pivot point into the local area network.\nThe risk implication is critical, as networking equipment typically resides at the perimeter of an organization or residential network, exposing the management interface or vulnerable parsing mechanisms to potential attackers.\nThe attack requires network connectivity to the vulnerable routing interface and does not necessitate prior authentication or specialized privileges, lowering the barrier to entry for malicious actors targeting embedded devices.",
  "technicalDetails": "The vulnerability exists within the firmware of the Tenda W20E v.16.01.0.6(2782), specifically inside the function designated as url_need_login.\nThe root cause stems from insecure input validation and the improper sanitization of parameters passed into the execution context of the underlying Linux operating system via the vulnerable function.\nThe affected component is exposed via the web-based management interface, making the attack vector network-accessible. An unauthenticated remote attacker can interact with the HTTP service hosted on the router to trigger the flawed parsing logic.\nDuring a typical attack flow, the adversary crafts a malicious HTTP request containing specially engineered input targeted at the url_need_login function. Because the application fails to adequately sanitize or restrict metacharacters within the input parameters, the supplied payload is improperly handled and subsequently passed to a system execution sink, such as a shell invocation function.\nUpon processing the malicious payload, the operating system executes the injected commands with the elevated privileges of the web server process, which frequently runs as the root user on embedded router architectures.\nThe payload behavior allows the execution of arbitrary system commands, enabling the attacker to read or write sensitive files, establish persistent backdoors, modify firewall configurations, or disrupt network operations.\nPost-exploitation impact includes complete system compromise, interception of traversing network traffic, DNS manipulation, and the potential utilization of the compromised router as a staging ground for lateral movement into connected internal network segments."
}