CVE-2025-22900: Stack Overflow Vulnerability in Totolink N600R Leading to Potential System Compromise

Overview

The vulnerability designated as CVE-2025-22900 is a serious security flaw discovered in Totolink N600R v4.3.0cu.7647_B20210106. It primarily affects users of the Totolink N600R, a popular wireless router. The vulnerability lies in a stack overflow that can be triggered by the macCloneMac parameter in the setWanConfig function. This vulnerability is of particular concern as an attacker could exploit this flaw to compromise the system or possibly leak sensitive data.
The potential impacts of this vulnerability cannot be overstated. With the increasing number of devices connected to the internet, ensuring the security of networking devices such as routers is of paramount importance. A successful exploit of this vulnerability could give an attacker unauthorized access to the user’s network and connected devices.

Vulnerability Summary

CVE ID: CVE-2025-22900
Severity: Critical (CVSS:9.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System Compromise, Potential Data Leakage

Affected Products

Product | Affected Versions

Totolink N600R | v4.3.0cu.7647_B20210106

How the Exploit Works

The exploit works by sending a specially crafted request to the target device, including the macCloneMac parameter within the setWanConfig function. The macCloneMac parameter is not properly sanitized by the system, leading to a stack overflow condition. The overflow condition can allow an attacker to execute arbitrary code or disrupt the normal functioning of the device.

Conceptual Example Code

The following is a conceptual example of how the vulnerability might be exploited. This could be a sample HTTP request, shell command, or pseudocode.

POST /setWanConfig HTTP/1.1
Host: target_router_ip
Content-Type: application/json
{ "macCloneMac": "Overflowing string value here" }

In this example, the macCloneMac parameter is being set with an overly long string value, which triggers the stack overflow condition in the setWanConfig function.

Mitigation Guidance

In response to this vulnerability, users are advised to apply the patch provided by the vendor as soon as possible. If the patch cannot be applied immediately, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation measure. However, these should not replace patching the system as they only provide a layer of defense and do not remove the vulnerability.