CVE-2025-4354: Critical Stack-Based Buffer Overflow Vulnerability in Tenda DAP-1520

Overview

A serious vulnerability has been identified in the Tenda DAP-1520 1.10B04_BETA02, a popular network optimization device used in various sectors. This vulnerability, designated as CVE-2025-4354, is classified as critical and possesses the potential to compromise systems or lead to data leakage. Being a stack-based buffer overflow vulnerability, it poses a significant risk as it can be remotely exploited by attackers, thereby necessitating immediate attention and mitigation.

Vulnerability Summary

CVE ID: CVE-2025-4354
Severity: Critical, CVSS 8.8
Attack Vector: Remote
Privileges Required: Low
User Interaction: None
Impact: System compromise, Data leakage

Affected Products

Product | Affected Versions

Tenda DAP-1520 | 1.10B04_BETA02

How the Exploit Works

The vulnerability lies in the function check_dws_cookie of the file /storage in the affected Tenda device. The manipulation of this function leads to a stack-based buffer overflow. A buffer overflow occurs when more data is put into a fixed-length buffer than it can handle, causing the extra data to overflow, overwrite adjacent memory, and potentially execute arbitrary code. In this case, a remote attacker can exploit this vulnerability to compromise the system or leak data.

Conceptual Example Code

Here’s a conceptual example of how a HTTP request may exploit this vulnerability:

POST /storage/check_dws_cookie HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "buffer_overflow": "A_LONG_STRING_THAT_CAUSES_OVERFLOW..." }

In this example, the “buffer_overflow” field contains a string that is longer than what the buffer in the function check_dws_cookie can handle, causing a buffer overflow and potentially allowing arbitrary code execution.

Mitigation Guidance

As a critical vulnerability with a public exploit, CVE-2025-4354 requires immediate mitigation. Users of the affected Tenda DAP-1520 version are advised to apply the vendor patch as soon as it becomes available. Until then, temporary mitigation can be achieved by using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) to detect and block exploit attempts. As always, it is recommended to keep all systems and software up-to-date to prevent exploitation of known vulnerabilities.