Description

A weakness has been identified in Tenda CP3 27.5.57.101. This issue affects some unknown processing of the file Net/NetCheckPing.cpp. This manipulation of the argument interface_name/host causes os command injection. The attack can be initiated remotely.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.1",
  "pubDate": "2026-09-05T22:17:18.943Z",
  "pubdate": "2026-09-05T22:17:18.943Z",
  "executiveSummary": "A critical OS command injection vulnerability has been identified in Tenda CP3 firmware version 27.5.57.101. The flaw exists within the processing logic of the Net/NetCheckPing.cpp file, specifically concerning the improper sanitization of the 'interface_name' and 'host' parameters.\nThis vulnerability allows an unauthenticated, remote attacker to inject and execute arbitrary system commands on the underlying operating system with elevated privileges.\nThe exploitation of this flaw poses a severe risk to the confidentiality, integrity, and availability of the affected device. Successful exploitation results in full device compromise, potentially allowing the attacker to establish persistence, pivot within the internal network, or manipulate traffic flows. Given the remote accessibility of the vector, the attack surface is significantly exposed, necessitating immediate defensive action to restrict unauthorized input to the affected interface.",
  "technicalDetails": "The vulnerability resides in the firmware's handling of network diagnostic requests, specifically localized within the Net/NetCheckPing.cpp source file. The system processes user-supplied input intended for interface configuration or host connectivity verification without adequate validation or containment mechanisms.\nThe root cause is identified as an injection vulnerability stemming from the concatenation of untrusted user input directly into a system-level command execution primitive. When the device processes the 'interface_name' or 'host' arguments, it fails to perform necessary shell meta-character filtering or input length validation. Consequently, an attacker can append malicious shell sequences (e.g., using delimiters such as ';', '|', or '&&') to these parameters to terminate the intended command and execute arbitrary secondary commands.\nThe attack flow proceeds as follows: First, the attacker identifies a reachable network service that interacts with the vulnerable Ping diagnostic function. Second, the attacker crafts a malicious payload containing shell injection operators followed by arbitrary commands (such as spawning a reverse shell or fetching remote binaries via wget or curl). Third, the attacker transmits this request, often via HTTP POST or GET parameters, to the device's web interface or management API. Finally, the server-side code in Net/NetCheckPing.cpp passes the tainted input to a system call function, such as system(), popen(), or exec(), which executes the command within the context of the root user or the web server service account.\nBecause the input is processed by the diagnostic subsystem, the injected commands execute with the process's privileges, which are typically high in embedded Linux environments. There is no requirement for prior authentication or local network access if the management interface is exposed to the WAN. The post-exploitation impact includes complete administrative control, unauthorized access to sensitive configuration files, and the potential to turn the Tenda CP3 into a component of a botnet or a platform for further internal reconnaissance."
}