CVE-2025-28024: Buffer Overflow Vulnerability in TOTOLINK A810R V4.1.2cu.5182_B20201026

Overview

In the ever-evolving landscape of cybersecurity, vulnerabilities present a constant challenge. One such vulnerability has been discovered in TOTOLINK A810R V4.1.2cu.5182_B20201026, identified as CVE-2025-28024. This vulnerability affects the cstecgi.cgi and has the potential to lead to a buffer overflow situation, which can result in system compromise or data leakage. Given the prevalence of TOTOLINK products, this vulnerability could potentially affect a vast array of systems, making it a matter of significant concern for cybersecurity professionals.

Vulnerability Summary

CVE ID: CVE-2025-28024
Severity: Critical (9.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System Compromise, Data Leakage

Affected Products

Product | Affected Versions

TOTOLINK A810R | V4.1.2cu.5182_B20201026

How the Exploit Works

The vulnerability in TOTOLINK A810R V4.1.2cu.5182_B20201026 exists due to inadequate bounds checking on user-supplied data in the cstecgi.cgi. This can result in a buffer overflow condition where an attacker can inject malicious code. If the malicious payload is crafted correctly, it can overwrite the software’s stack, leading to arbitrary code execution. This can further lead to a total system compromise or data leakage.

Conceptual Example Code

Here is a conceptual example of how the vulnerability might be exploited via an HTTP request:

POST /cstecgi.cgi HTTP/1.1
Host: vulnerable-device-ip
Content-Type: application/x-www-form-urlencoded
overflow_data=AAAAAAAAAAAAAAAAAAAAAAAAA...[repeat 'A' until overflow]...+malicious_code

In this example, the “overflow_data” parameter is filled with a large amount of ‘A’ characters, causing a buffer overflow. Following this, the attacker’s malicious code is attached, which would be executed due to the overflow.

Mitigation

Users are advised to apply the vendor patch as soon as it becomes available. Until then, implementing a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can serve as a temporary mitigation. Always practice safe cybersecurity hygiene by limiting exposure of critical systems and maintaining up-to-date backups.