Overview
A critical vulnerability, CVE-2025-3992, has been identified in TOTOLINK N150RT 3.4.0-B20190525. This vulnerability allows remote attackers to initiate a buffer overflow attack, potentially leading to a system compromise or data leakage. As the exploit has been publicly disclosed, unpatched systems are at high risk. This post aims to provide a detailed understanding of this vulnerability, its potential impact, and the necessary mitigation steps to prevent exploits.
Vulnerability Summary
CVE ID: CVE-2025-3992
Severity: Critical (CVSS 8.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
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Product | Affected Versions
TOTOLINK N150RT | 3.4.0-B20190525
How the Exploit Works
The vulnerability lies in the unknown code of the file /boafrm/formWlwds in TOTOLINK N150RT. The flaw arises from the improper handling of the argument ‘submit-url. An attacker can manipulate this argument to cause a buffer overflow. A buffer overflow occurs when more data is put into a buffer than it can handle, causing an overflow of data into adjacent memory spaces. This is a dangerous scenario as it can lead to arbitrary code execution, allowing an attacker to take control of the system or leak sensitive data.
Conceptual Example Code
A conceptual example of exploiting this vulnerability might look like the following HTTP request. This request manipulates the ‘submit-url’ argument with a malicious payload that triggers the buffer overflow:
POST /boafrm/formWlwds HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
submit-url=...[malicious_payload]...The ‘malicious_payload’ here would be designed to overflow the buffer and execute arbitrary code or exfiltrate data.
Mitigation Guidance
To remediate this vulnerability, the recommended course of action is to apply a vendor patch. This will fix the flaw in the affected software and prevent any future exploits. In case a patch is not immediately available or cannot be applied promptly, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation measure. These measures can monitor and block suspicious activities, thus providing some level of protection against the exploit.