CVE-2025-5910: Critical Buffer Overflow Vulnerability in TOTOLINK EX1200T

Overview

A critical vulnerability has been discovered in the TOTOLINK EX1200T up to version 4.1.2cu.5232_B20210713. This vulnerability, identified as CVE-2025-5910, affects an unknown function of the file /boafrm/formWsc, which is a component of the HTTP POST Request Handler. What makes this vulnerability particularly concerning is the fact that it can be exploited remotely, and the details of the exploit have already been made public. This means that potential attackers are more likely to exploit it, leading to a higher risk for users.

Vulnerability Summary

CVE ID: CVE-2025-5910
Severity: Critical, CVSS score 8.8
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage

Affected Products

Product | Affected Versions

TOTOLINK EX1200T | Up to 4.1.2cu.5232_B20210713

How the Exploit Works

The vulnerability stems from a buffer overflow condition within the HTTP POST Request Handler’s handling of the /boafrm/formWsc file. If an attacker crafts a malicious HTTP POST request with an oversized payload, it could overflow the buffer and cause undefined behavior in the system. This could allow the attacker to execute arbitrary code, potentially leading to system compromise or data leakage.

Conceptual Example Code

The following is a conceptual example of how an attacker might exploit this vulnerability. Please note that this is a simplified representation and actual attack may involve more complex payloads.

POST /boafrm/formWsc HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
param1=value1&param2=value2&...&paramN=very_long_string_exceeding_buffer_capacity

In the above example, `paramN` is the parameter that the attacker uses to overflow the buffer, where `very_long_string_exceeding_buffer_capacity` is a string that exceeds the capacity of the buffer.

Mitigation

Users are advised to apply vendor provided patches as soon as possible. If the patch cannot be applied immediately, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation. However, these measures cannot fully protect against the vulnerability and are only intended as a stop-gap until the patch can be applied.