Overview
The cybersecurity landscape is fraught with a broad spectrum of vulnerabilities, and in this post, we will be delving into the critical buffer overflow vulnerability identified as CVE-2025-5909. This vulnerability has been found in TOTOLINK EX1200T versions up to 4.1.2cu.5232_B20210713. It poses a significant threat due to its critical severity score and its potential to be exploited remotely. This vulnerability matters because it can lead to a system compromise or possible data leakage, endangering the integrity of the network and the data it houses.
Vulnerability Summary
CVE ID: CVE-2025-5909
Severity: Critical, CVSS Score 8.8
Attack Vector: Remote
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage
Affected Products
Escape the Surveillance Era
Most apps won’t tell you the truth.
They’re part of the problem.
Phone numbers. Emails. Profiles. Logs.
It’s all fuel for surveillance.
Ameeba Chat gives you a way out.
- • No phone number
- • No email
- • No personal info
- • Anonymous aliases
- • End-to-end encrypted
Chat without a trace.
Product | Affected Versions
TOTOLINK EX1200T | up to 4.1.2cu.5232_B20210713
How the Exploit Works
The exploit takes advantage of an unknown function in the /boafrm/formReflashClientTbl file of the HTTP POST Request Handler component in TOTOLINK EX1200T. The attacker manipulates the buffer, causing it to overflow. This overflow can potentially cause erratic program behavior, leading to system crashes, incorrect outputs, and the execution of malicious code. As this vulnerability can be exploited remotely, it makes the attack vector even more threatening.
Conceptual Example Code
Below is a conceptual HTTP POST request that demonstrates how an attacker might exploit this vulnerability:
POST /boafrm/formReflashClientTbl HTTP/1.1
Host: target.example.com
Content-Type: application/json
{
"overflow_data": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA..."
}In the above example, the “overflow_data” key carries a payload that is larger than what the system buffer can handle, leading to a buffer overflow.
Mitigation Guidance
As the vulnerability has been publicly disclosed, it is imperative to apply a vendor patch as soon as it’s available. In the meantime, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation measure, providing some protection against potential exploitation attempts. Always remember, staying up-to-date with such vulnerabilities and their patches can make the difference between maintaining secure systems and falling victim to a cyber attack.