CVE-2025-4142: Critical Buffer Overflow Vulnerability in Netgear EX6200 1.0.3.94

Overview

A critical vulnerability has been discovered in Netgear EX6200 version 1.0.3.94 that has been assigned the CVE ID of CVE-2025-4142. This vulnerability is associated with the function sub_3C8EC of the software and can lead to a buffer overflow attack, potentially compromising the system and causing data leakage. As it can be initiated remotely, the risk is severe, and any organization using the vulnerable version of Netgear EX6200 is at risk. The vendor has been contacted about the vulnerability but has yet to respond, making immediate mitigation a priority for all affected systems.

Vulnerability Summary

CVE ID: CVE-2025-4142
Severity: Critical (CVSS 8.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System Compromise and Data Leakage

Affected Products

Product | Affected Versions

Netgear EX6200 | 1.0.3.94

How the Exploit Works

The vulnerability resides in the function sub_3C8EC of Netgear EX6200 version 1.0.3.94. By manipulating the ‘host’ argument in the function, an attacker can trigger a buffer overflow. This can lead to arbitrary code execution, allowing the attacker to compromise the system. Furthermore, since the attack can be launched remotely, the attacker does not need physical access to the target system, making it a highly severe vulnerability.

Conceptual Example Code

The following is a conceptual example of how this vulnerability might be exploited. This is not an actual exploit code but a hypothetical example to demonstrate the concept of the attack.

POST /sub_3C8EC/function HTTP/1.1
Host: vulnerable_netgear_ex6200
Content-Type: application/json
{ "host": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA..." }

In this example, the ‘host’ argument is filled with an excessively long string (represented by ‘A’s), causing a buffer overflow in the vulnerable function.

Mitigation

Currently, the vendor has not provided a patch for this vulnerability. Therefore, it is recommended to implement a Web Application Firewall (WAF) or Intrusion Detection System (IDS) as a temporary mitigation measure. These measures can help detect and block exploit attempts. However, they do not eliminate the vulnerability, so it’s crucial to apply the vendor’s patch as soon as it becomes available. Furthermore, consider implementing a defense-in-depth strategy to reduce the overall risk to your systems.