Description

A vulnerability was found in Comfast CF-N1-S 2.6.0.1. This impacts the function sub_44B50C of the file /cgi-bin/mbox-config?method=SET&section=ptest_channel of the component Web Management. The manipulation results in stack-based buffer overflow. The attack can be launched remotely. The exploit has been made public and could be used.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.9",
  "pubDate": "2026-08-20T19:17:04.710Z",
  "pubdate": "2026-08-20T19:17:04.710Z",
  "executiveSummary": "A critical stack-based buffer overflow vulnerability has been identified in the Comfast CF-N1-S 2.6.0.1 firmware. This security flaw resides within the Web Management component, specifically targeting the function sub_44B50C accessible via the endpoint /cgi-bin/mbox-config?method=SET&section=ptest_channel.\nThe vulnerability allows remote attackers to trigger a memory corruption condition by supplying excessively long input parameters to the vulnerable CGI binary. Successful exploitation can lead to arbitrary code execution, system instability, or a complete denial of service (DoS) of the affected networking device.\nGiven that public exploit code has been released and the attack vector is exposed over the network without explicit authentication restrictions mentioned in the initial vector, the risk implication is severe. Unauthenticated or remote threat actors can leverage this flaw to compromise the integrity and availability of the underlying operating system.\nRemediation requires applying vendor-supplied patches if available, restricting administrative access to trusted internal networks, disabling unnecessary remote management services, and implementing strict input validation controls within the web application layer to prevent buffer overruns.",
  "technicalDetails": "The vulnerability is a classic stack-based buffer overflow stemming from unsafe memory handling operations within the function sub_44B50C. This function processes parameters supplied through the HTTP CGI endpoint located at /cgi-bin/mbox-config?method=SET&section=ptest_channel.\nThe root cause lies in the failure of the application to properly bound-check user-supplied input copied into fixed-size local buffers allocated on the stack. When an attacker sends a specially crafted HTTP request containing an oversized payload within the query string or POST data parameters handled by the SET method and ptest_channel section, the input overflows the destination buffer boundaries.\nThis overflow overwrites adjacent stack memory structures, including saved frame pointers and return addresses. When the vulnerable function sub_44B50C attempts to return execution control to the calling function, the instruction pointer is redirected to the attacker-controlled memory address, potentially enabling the execution of arbitrary shellcode or payloads injected into the stack.\nThe attack vector is network-based, meaning an attacker with reachability to the web management interface of the Comfast CF-N1-S device can initiate the exploit remotely. The affected component is the Web Management CGI binary running on version 2.6.0.1. Because a public exploit has been made available, malicious actors can automate the delivery of the malicious payload, increasing the probability of successful exploitation.\nPost-exploitation impact includes full system compromise, persistent unauthorized access, execution of arbitrary commands with the privileges of the web server daemon, and potential pivot opportunities within the local network segment where the vulnerable router or access point is deployed."
}