CVE-2025-3803: Critical Vulnerability in Tenda W12 and i24 3.0.0.4/3.0.0.5 Resulting in Stack-Based Buffer Overflow

Overview

In today’s cybersecurity landscape, a new critical vulnerability has been identified, labeled as CVE-2025-3803. It primarily affects Tenda’s W12 and i24 devices running firmware versions 3.0.0.4(2887) and 3.0.0.5(3644), respectively. This flaw is of paramount importance due to the fact that it could lead to potential system compromise or data leakage, posing a significant threat to data integrity and confidentiality.

Vulnerability Summary

CVE ID: CVE-2025-3803
Severity: Critical (CVSS Severity Score: 8.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise, potential data leakage

Affected Products

Product | Affected Versions

Tenda W12 | 3.0.0.4(2887)
Tenda i24 | 3.0.0.5(3644)

How the Exploit Works

The vulnerability lies within the cgiSysScheduleRebootSet function of the /bin/httpd file. This function handles the arguments for rebooting the device. The exploit takes advantage of the manipulation of the “rebootDate” argument, leading to a stack-based buffer overflow. This overflow can cause the system to execute arbitrary code, potentially compromising the system or leading to data leakage. The vulnerability can be exploited remotely, and the details have been disclosed to the public.

Conceptual Example Code

Here is a simplified conceptual example of a malicious HTTP request that could exploit this vulnerability:

POST /cgi-bin/httpd?rebootDate HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "rebootDate": "A long string that causes a buffer overflow..." }

In this example, the attacker sends a POST request to the device’s server with an excessively long “rebootDate” value. This results in a buffer overflow that could allow the execution of arbitrary code.

Mitigation Guidance

To mitigate this vulnerability, it is advised to apply the vendor patch as soon as it is available. If the patch is not yet available or cannot be applied immediately, using a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) can provide temporary mitigation. These systems can detect and block malicious requests, preventing the exploit from being successful. Please ensure to always keep your systems updated to the latest firmware to prevent such vulnerabilities.