CVE-2025-10432: Tenda AC1206 Buffer Overflow Vulnerability

CVE-2025-10432 Overview

A critical stack-based buffer overflow vulnerability has been identified in Tenda AC1206 router firmware version 15.03.06.23. This vulnerability exists in the check_param_changed function within the /goform/AdvSetMacMtuWa endpoint of the HTTP Request Handler component. By manipulating the wanMTU argument, a remote attacker can trigger a buffer overflow condition that may lead to arbitrary code execution or denial of service on vulnerable devices.

Critical Impact

Remote unauthenticated attackers can exploit this stack-based buffer overflow to potentially achieve arbitrary code execution on vulnerable Tenda AC1206 routers, compromising network security and enabling further lateral movement within affected environments.

Affected Products

• Tenda AC1206 Firmware version 15.03.06.23
• Tenda AC1206 Hardware

Discovery Timeline

• September 15, 2025 - CVE-2025-10432 published to NVD
• September 20, 2025 - Last updated in NVD database

Technical Details for CVE-2025-10432

Vulnerability Analysis

This vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), specifically manifesting as a stack-based buffer overflow. The vulnerable component resides within the HTTP Request Handler of the Tenda AC1206 router's web management interface.

The check_param_changed function fails to properly validate the length of user-supplied input passed through the wanMTU parameter. When an attacker sends a specially crafted HTTP request to the /goform/AdvSetMacMtuWa endpoint with an oversized wanMTU value, the function copies this data to a fixed-size stack buffer without adequate bounds checking. This allows the attacker to overwrite adjacent stack memory, including the return address, potentially redirecting execution flow to attacker-controlled code.

The network-accessible nature of this vulnerability, combined with no authentication requirements, makes it particularly dangerous for exposed devices. A proof of concept has been published on GitHub, increasing the likelihood of exploitation in the wild.

Root Cause

The root cause of this vulnerability is insufficient input validation in the check_param_changed function. The function allocates a fixed-size buffer on the stack to store the wanMTU parameter value but does not verify that the input length does not exceed the buffer capacity before copying the data. This classic buffer overflow pattern allows attackers to corrupt stack memory by providing input that exceeds the expected bounds.

Attack Vector

The attack vector is network-based, requiring no prior authentication. An attacker can exploit this vulnerability by sending a malicious HTTP POST request to the /goform/AdvSetMacMtuWa endpoint on a vulnerable Tenda AC1206 router. The attack payload is delivered via the wanMTU parameter, where an oversized value triggers the buffer overflow condition.

The exploitation process involves crafting an HTTP request with a wanMTU parameter containing data that exceeds the stack buffer's capacity, followed by shellcode or ROP gadgets to achieve code execution. Technical details and a proof of concept are available in the IoT vulnerability research repository.

Detection Methods for CVE-2025-10432

Indicators of Compromise

• Unusual HTTP POST requests to /goform/AdvSetMacMtuWa with abnormally large wanMTU parameter values
• Router crashes, unexpected reboots, or unresponsive web management interface
• Suspicious outbound network connections originating from the router to unknown external IP addresses
• Unexpected configuration changes or new user accounts on the router

Detection Strategies

• Implement network intrusion detection rules to identify HTTP requests targeting /goform/AdvSetMacMtuWa with oversized payload parameters
• Monitor router logs for repeated access attempts to the vulnerable endpoint
• Deploy anomaly detection for unusual traffic patterns originating from or destined to IoT devices

Monitoring Recommendations

• Enable comprehensive logging on network perimeter devices to capture traffic to Tenda router management interfaces
• Implement network segmentation to isolate IoT devices from critical network infrastructure
• Configure SIEM alerts for any traffic matching known exploitation patterns for Tenda router vulnerabilities

How to Mitigate CVE-2025-10432

Immediate Actions Required

• Restrict access to the Tenda AC1206 web management interface to trusted internal networks only
• Disable remote management features if not required
• Implement firewall rules to block external access to port 80/443 on the router's management interface
• Consider network segmentation to isolate the vulnerable device from critical assets

Patch Information

At the time of publication, no official patch from Tenda has been confirmed for this vulnerability. Users should monitor the Tenda official website for firmware updates that address CVE-2025-10432. Additional technical details can be found in the VulDB advisory.

Workarounds

• Configure access control lists (ACLs) to restrict management interface access to specific trusted IP addresses only
• Place the router behind an additional firewall that filters malicious HTTP requests
• If feasible, consider replacing the affected device with a router from a vendor that provides timely security updates
• Disable the web management interface entirely and use alternative management methods if available

# Example firewall rule to block external access to router management
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP