CVE-2024-8578: Totolink T8 Buffer Overflow Vulnerability

CVE-2024-8578 Overview

CVE-2024-8578 is a buffer overflow vulnerability in the TOTOLINK AC1200 T8 router running firmware version 4.1.5cu.861_B20230220. The flaw resides in the setWiFiMeshName function within /cgi-bin/cstecgi.cgi, where the device_name argument is copied without proper bounds checking [CWE-120]. Attackers can trigger the overflow remotely across the network. The exploit details have been publicly disclosed, and TOTOLINK did not respond to the disclosure attempt. The vulnerability affects both the firmware image and the physical T8 hardware line.

Critical Impact
Remote attackers with low privileges can corrupt router memory through the device_name parameter, leading to potential code execution or denial of service on affected TOTOLINK T8 devices.

Affected Products

TOTOLINK T8 Firmware 4.1.5cu.861_B20230220
TOTOLINK AC1200 T8 hardware
/cgi-bin/cstecgi.cgi CGI handler (setWiFiMeshName function)

Discovery Timeline

2024-09-08 - CVE-2024-8578 published to NVD with public proof-of-concept disclosure
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-8578

Vulnerability Analysis

The vulnerability is a classic stack or heap buffer overflow [CWE-120] in the router's web management CGI. TOTOLINK exposes device configuration endpoints via /cgi-bin/cstecgi.cgi, which dispatches JSON requests to internal handlers such as setWiFiMeshName. When this handler processes the device_name argument, it copies the caller-supplied string into a fixed-size buffer without validating length. Supplying an oversized value corrupts adjacent memory. Because the CGI runs with elevated privileges on the embedded Linux system, successful memory corruption can result in arbitrary code execution or a persistent denial of service on the router.

Root Cause

The root cause is missing input length validation on the device_name field before it is copied into a stack-allocated buffer inside setWiFiMeshName. TOTOLINK firmware in this class typically uses unsafe string operations such as strcpy or sprintf on attacker-controlled JSON fields parsed from the HTTP request body, with no bounds enforcement between the parser and handler.

Attack Vector

The attack vector is network-based against the router's HTTP management interface. An authenticated user with low privileges can send a crafted POST request to /cgi-bin/cstecgi.cgi invoking the setWiFiMeshName topic with an overlong device_name value. Where the management interface is exposed to the WAN or reachable across a flat network, remote attackers can reach the endpoint directly. Public technical details are available in the GitHub PoC repository and the VulDB entry #276812.

No verified exploit code is republished here. Refer to the public PoC for the exact request structure and payload length required to trigger the overflow.

Detection Methods for CVE-2024-8578

Indicators of Compromise

HTTP POST requests to /cgi-bin/cstecgi.cgi containing the setWiFiMeshName topic with abnormally long device_name values.
Router web service crashes, unexpected reboots, or httpd/cstecgi process restarts recorded in device logs.
Unauthenticated or low-privileged sessions targeting mesh configuration endpoints outside normal administrative windows.
New outbound connections from the router to unknown hosts following administrative interface activity.

Detection Strategies

Inspect network traffic to the router management interface for POST bodies where device_name exceeds expected string length (typically a few dozen bytes).
Alert on repeated cstecgi.cgi requests from a single source that trigger HTTP 5xx responses or connection resets.
Baseline legitimate administrative behavior and flag deviations such as mesh configuration changes from non-admin subnets.

Monitoring Recommendations

Forward router syslog and web server logs to a centralized logging platform and retain requests targeting /cgi-bin/cstecgi.cgi.
Monitor for unusual DNS lookups or outbound traffic from the router itself, which may indicate post-exploitation activity.
Track firmware version inventory to identify all AC1200 T8 devices running 4.1.5cu.861_B20230220 across the network.

How to Mitigate CVE-2024-8578

Immediate Actions Required

Restrict access to the router web management interface to trusted administrative VLANs and block WAN-side exposure.
Rotate router administrative credentials, since exploitation requires low-privileged authentication.
Disable the mesh configuration feature if it is not in use in your deployment.
Isolate affected TOTOLINK T8 devices behind an upstream firewall until a vendor patch is available.

Patch Information

No vendor patch is currently referenced in the NVD entry. According to the CVE description, TOTOLINK was contacted about the disclosure but did not respond. Monitor the TOTOLINK official website for firmware updates addressing setWiFiMeshName input handling. Where feasible, replace end-of-support hardware with actively maintained models.

Workarounds

Place the router management interface on a dedicated management network reachable only via VPN.
Deploy network-layer access control lists that drop HTTP requests to /cgi-bin/cstecgi.cgi from non-administrative sources.
Configure an upstream web application firewall to reject requests where device_name exceeds a strict length limit.
Increase monitoring on the device and its adjacent network segments until a firmware fix is available.

bash

# Example upstream ACL restricting router management access to a jump host
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -s <admin_jump_host> -j ACCEPT
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -j DROP
iptables -A FORWARD -p tcp -d <router_ip> --dport 443 -s <admin_jump_host> -j ACCEPT
iptables -A FORWARD -p tcp -d <router_ip> --dport 443 -j DROP