CVE-2025-6098: UTT 750W Firmware Buffer Overflow Flaw

CVE-2025-6098 Overview

A critical buffer overflow vulnerability has been discovered in UTT 进取 750W router firmware up to version 5.0. The vulnerability exists in the strcpy function within the /goform/setSysAdm API endpoint, where improper handling of the passwd1 argument allows remote attackers to trigger a buffer overflow condition. This flaw can be exploited remotely without authentication, potentially enabling attackers to execute arbitrary code or cause denial of service on affected devices.

Critical Impact

Remote attackers can exploit this buffer overflow vulnerability to compromise UTT 750W routers, potentially gaining full control over the device or disrupting network operations. The vendor has been unresponsive to disclosure attempts.

Affected Products

• UTT 750W Firmware up to version 5.0
• UTT 750W Hardware devices

Discovery Timeline

• June 16, 2025 - CVE-2025-6098 published to NVD
• January 8, 2026 - Last updated in NVD database

Technical Details for CVE-2025-6098

Vulnerability Analysis

This vulnerability is classified as a buffer overflow (CWE-120) stemming from improper restriction of operations within memory buffer bounds (CWE-119). The flaw resides in the /goform/setSysAdm API endpoint, which handles system administration functions on the UTT 750W router. When processing the passwd1 parameter, the vulnerable code uses the unsafe strcpy function without proper bounds checking, allowing an attacker to supply an oversized input that overwrites adjacent memory regions.

The network-accessible nature of this vulnerability is particularly concerning for network infrastructure devices. An attacker can craft a malicious HTTP request to the affected endpoint with an excessively long passwd1 value, causing the strcpy function to write beyond the allocated buffer. This can corrupt the stack or heap, potentially leading to arbitrary code execution or system instability.

Root Cause

The root cause of this vulnerability is the use of the unsafe strcpy function to copy user-supplied input (passwd1 argument) into a fixed-size buffer without validating the input length. The strcpy function does not perform bounds checking, meaning it will continue copying bytes until it encounters a null terminator, regardless of the destination buffer's size. This classic memory safety issue allows attackers to overflow the buffer and overwrite critical memory structures.

Attack Vector

The attack vector is network-based and can be executed remotely. An attacker sends a specially crafted HTTP POST request to the /goform/setSysAdm endpoint on the vulnerable UTT 750W router. By manipulating the passwd1 parameter with an oversized payload, the attacker triggers the buffer overflow condition in the strcpy function.

The attack does not require authentication or user interaction, making it particularly dangerous for internet-exposed routers. Successful exploitation could result in:

• Remote code execution with elevated privileges on the router
• Complete device compromise and persistent backdoor installation
• Denial of service causing network disruption
• Use of the compromised router as a pivot point for further attacks

For technical details and proof-of-concept information, see the GitHub CVE Resource and VulDB Entry #312567.

Detection Methods for CVE-2025-6098

Indicators of Compromise

• Unexpected HTTP POST requests to /goform/setSysAdm with unusually large passwd1 parameter values
• Router instability, crashes, or unexpected reboots following network requests
• Anomalous process behavior or memory utilization on UTT 750W devices
• Unauthorized configuration changes or administrative access to the router

Detection Strategies

• Monitor network traffic for HTTP requests targeting /goform/setSysAdm endpoints with oversized payloads
• Implement intrusion detection rules to flag requests with abnormally long parameter values in POST data
• Configure web application firewalls (WAF) to block requests exceeding expected input lengths for administrative endpoints
• Analyze router logs for repeated failed authentication attempts or unusual API access patterns

Monitoring Recommendations

• Enable comprehensive logging on UTT 750W routers to capture all administrative API requests
• Deploy network monitoring solutions to detect potential exploit attempts against IoT and router devices
• Establish baseline network behavior to identify anomalous traffic patterns targeting management interfaces
• Consider network segmentation to isolate router management interfaces from untrusted networks

How to Mitigate CVE-2025-6098

Immediate Actions Required

• Restrict network access to the router's administrative interface to trusted IP addresses only
• Disable remote administration features if not required for operations
• Implement firewall rules to block external access to management ports and web interfaces
• Monitor for and apply any firmware updates from UTT when they become available

Patch Information

As of the last update, the vendor (UTT) has not responded to disclosure attempts and no official patch has been released. Organizations using affected UTT 750W devices should implement compensating controls until an official fix is available. Monitor the VulDB Entry and GitHub CVE Resource for updates on remediation status.

Workarounds

• Place UTT 750W routers behind a firewall that restricts access to management interfaces
• Use VPN or jump hosts to access router administration rather than exposing interfaces directly
• Consider replacing vulnerable devices with alternative router hardware from vendors with responsive security practices
• Implement network access control lists (ACLs) to limit which hosts can communicate with the router's web interface

# Example firewall rule to restrict access to router management interface
# Allow only trusted management network to access web interface
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP