CVE-2025-3990: Critical Buffer Overflow Vulnerability in TOTOLINK N150RT

Overview

A critical security vulnerability identified as CVE-2025-3990 has been discovered in TOTOLINK’s N150RT router, specifically affecting version 3.4.0-B20190525. This vulnerability is of significant concern due to the potential for remote exploitation, leading to system compromise or data leakage. The issue lies within an unknown functionality of the file /boafrm/formVlan, which can be manipulated via the argument “submit-url” to trigger a buffer overflow condition. Given that the exploit details for this vulnerability have been publicly disclosed, the risk of exploitation is considerably high.

Vulnerability Summary

CVE ID: CVE-2025-3990
Severity: Critical (CVSS: 8.8)
Attack Vector: Remote
Privileges Required: None
User Interaction: None
Impact: Potential system compromise and data leakage

Affected Products

Product | Affected Versions

TOTOLINK N150RT | 3.4.0-B20190525

How the Exploit Works

The vulnerability exists due to insufficient boundary checks within the file /boafrm/formVlan. An attacker can manipulate the “submit-url” argument to cause a buffer overflow condition. This overflow can lead to unauthorized access to the system or potential data leakage. Given that the vulnerability can be exploited remotely, it opens up the possibility for attackers to compromise systems without needing physical access or user interaction.

Conceptual Example Code

Below is a conceptual example of how an HTTP request exploiting this vulnerability might look. Note that actual exploit code would contain specific payload designed to cause the buffer overflow.

POST /boafrm/formVlan HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
submit-url=<malicious_payload>

The `` would be crafted to exceed the buffer size, causing an overflow. The specifics of this payload would depend on the exact nature of the buffer overflow vulnerability.

Mitigation Guidance

Users of affected versions are advised to apply the vendor-supplied patch as soon as possible to mitigate this vulnerability. In the event that a patch cannot be applied immediately, the use of a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used as a temporary mitigation measure. These systems can be set up to detect and block attempts to exploit this vulnerability. However, they should not be considered as a long-term solution, as they may not be able to fully prevent a sophisticated attack. The ultimate solution is to patch the affected systems promptly.