CVE-2024-0539: Critical Stack-Based Buffer Overflow Vulnerability in Tenda W9 1.0.0.7(4456)

Overview

This article provides an in-depth analysis of a critical vulnerability, CVE-2024-0539, found in the Tenda W9 1.0.0.7(4456). This vulnerability affects the function formQosManage_user of the httpd component and could lead to a potential system compromise or data leakage. Given the severity of this security flaw, it is of paramount importance that developers, security professionals, and system administrators understand the nature of the vulnerability and take immediate steps to mitigate its risks.

Vulnerability Summary

CVE ID: CVE-2024-0539
Severity: Critical, CVSS score 8.8
Attack Vector: Network (Remote)
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

Tenda W9 | 1.0.0.7(4456)

How the Exploit Works

The vulnerability resides in the formQosManage_user function of the httpd component. An attacker can exploit this vulnerability by manipulating the ssidIndex argument, leading to a stack-based buffer overflow. This overflow can then allow the attacker to execute arbitrary code or disrupt the normal operation of the system, potentially leading to system compromise or data leakage.

Conceptual Example Code

Below is a conceptual example of how this vulnerability might be exploited. This example is provided to give a sense of how an attacker might craft a malicious HTTP request to exploit the vulnerability.

POST /formQosManage_user HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
ssidIndex=1; payload=%s

In this example, `%s` represents a string that exceeds the buffer’s capacity, causing a buffer overflow. Please note that this is a conceptual example and the actual exploit may involve more complex manipulations.

Vulnerability Mitigation

Given the critical nature of this vulnerability, it is recommended to apply the vendor patch as soon as it becomes available. If the vendor does not provide a patch, or if applying the patch is not immediately feasible, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. These stopgap measures can detect and prevent exploitation attempts, but they do not resolve the underlying vulnerability. Therefore, they should be used as part of a layered security approach, not as a standalone solution.