CVE-2025-28034: Remote Command Execution Vulnerability in TOTOLINK Wireless Routers

Overview

In this blog post, we are going to discuss a critical cybersecurity vulnerability identified as CVE-2025-28034, which poses a significant threat to a series of wireless routers produced by TOTOLINK. The affected products, due to a flaw in the NTPSyncWithHost function, have been found susceptible to pre-auth remote command execution attacks, which could potentially lead to system compromise or data leakage. Given the CVSS Severity Score of 9.8, this vulnerability is of paramount importance and requires immediate attention and mitigation.

Vulnerability Summary

CVE ID: CVE-2025-28034
Severity: Critical (CVSS: 9.8)
Attack Vector: Remote Network
Privileges Required: None
User Interaction: None
Impact: System compromise or data leakage

Affected Products

Product | Affected Versions

TOTOLINK A800R | V4.1.2cu.5137_B20200730
TOTOLINK A810R | V4.1.2cu.5182_B20201026
TOTOLINK A830R | V4.1.2cu.5182_B20201102
TOTOLINK A950RG | V4.1.2cu.5161_B20200903
TOTOLINK A3000RU | V5.9c.5185_B20201128
TOTOLINK A3100R | V4.1.2cu.5247_B20211129

How the Exploit Works

The vulnerability resides in the NTPSyncWithHost function, which can be exploited through the hostTime parameter. An attacker can send a specially crafted request with malicious commands to this parameter. Since the vulnerability is pre-auth, the attacker doesn’t need any authentication details to execute this attack. Once the malicious request is processed, the router executes the commands, leading to a potential system compromise or data leakage.

Conceptual Example Code

Below is a conceptual example of how this vulnerability might be exploited. This example demonstrates a POST request with a malicious payload.

POST /NTPSyncWithHost HTTP/1.1
Host: vulnerable_router_ip
Content-Type: application/x-www-form-urlencoded
hostTime=;rm%20-rf%20/*;

In the above example, the malicious payload `;rm%20-rf%20/*;` is URL-encoded and is equivalent to `;rm -rf /*;` in shell command, which aims to delete all files in the system. The semicolons before and after the command ensure that it’s executed regardless of the original function of the hostTime parameter.