CVE-2025-7116: UTT 750W Buffer Overflow Vulnerability

CVE-2025-7116 Overview

CVE-2025-7116 is a buffer overflow vulnerability in the UTT 进取 750W router firmware through version 3.2.2-191225. The flaw resides in the /goform/Fast_wireless_conf endpoint, where the ssid parameter is not properly bounds-checked before being copied into a fixed-size buffer. Attackers can trigger the overflow remotely over the network. The exploit details have been publicly disclosed, increasing the likelihood of opportunistic exploitation. The vendor was contacted prior to disclosure but did not respond, leaving affected devices without an official fix at the time of publication.

Critical Impact

Remote attackers with low-privilege access can corrupt memory through the ssid parameter, enabling potential code execution and full compromise of the router.

Affected Products

• UTT 进取 750W router (hardware)
• UTT 750W firmware versions up to and including 3.2.2-191225
• Web management interface exposing /goform/Fast_wireless_conf

Discovery Timeline

• 2025-07-07 - CVE-2025-7116 published to the National Vulnerability Database (NVD)
• 2026-01-14 - Last updated in NVD database

Technical Details for CVE-2025-7116

Vulnerability Analysis

The vulnerability is a classic buffer overflow [CWE-119, CWE-120] in the wireless quick-configuration handler of the UTT 750W router. When a client submits a request to /goform/Fast_wireless_conf, the firmware reads the ssid parameter from the request body and copies it into a fixed-length stack or global buffer without validating the input length.

An attacker supplying an oversized ssid value can overwrite adjacent memory regions. Depending on the layout of the binary, this corruption can overwrite return addresses, function pointers, or control structures used by the embedded HTTP daemon. Successful exploitation can lead to arbitrary code execution on the device or a denial-of-service condition that disrupts network operations.

The attack requires network reachability to the router's management interface and low-privilege authentication. Routers exposed to LAN-side attackers, guest networks, or with WAN-side management enabled are at elevated risk.

Root Cause

The root cause is the absence of length validation on attacker-controlled input before a memory copy operation. The handler trusts the size of the ssid field as supplied by the client, violating safe coding practices for boundary-sensitive routines. This category of weakness is tracked under CWE-120: Buffer Copy without Checking Size of Input.

Attack Vector

Exploitation occurs over the network through a crafted HTTP POST request to /goform/Fast_wireless_conf containing an oversized ssid parameter. The exploit has been disclosed publicly in the GitHub CVE Documentation and indexed under VulDB #315027. Because the device does not currently have a patch, any reachable instance remains exposed to repeat exploitation attempts.

The vulnerability mechanism is described in prose only; no verified proof-of-concept code is reproduced here. See the linked references for full technical detail.

Detection Methods for CVE-2025-7116

Indicators of Compromise

• HTTP POST requests to /goform/Fast_wireless_conf containing abnormally long ssid values, typically exceeding 32–64 bytes.
• Unexpected reboots, web UI crashes, or httpd process restarts on UTT 750W devices following inbound configuration requests.
• New or unfamiliar administrative sessions originating from non-management subnets.

Detection Strategies

• Inspect HTTP traffic destined to UTT router management interfaces and alert on requests where the ssid field exceeds expected length boundaries.
• Deploy IDS/IPS signatures that match the URI path /goform/Fast_wireless_conf combined with oversized form parameters.
• Correlate router log events such as service restarts with preceding inbound HTTP traffic to the management endpoint.

Monitoring Recommendations

• Forward router syslog and HTTP access logs to a centralized logging or SIEM platform for retention and analysis.
• Baseline normal configuration-change traffic so anomalous Fast_wireless_conf activity stands out.
• Monitor for outbound connections initiated by the router itself, which may indicate post-exploitation command-and-control.

How to Mitigate CVE-2025-7116

Immediate Actions Required

• Restrict access to the router's web management interface to trusted management VLANs or jump hosts.
• Disable WAN-side remote management on the UTT 750W until a patched firmware is available.
• Rotate administrative credentials and audit existing accounts on affected devices.
• Place vulnerable devices behind a network firewall that enforces strict ACLs for HTTP/HTTPS management traffic.

Patch Information

At the time of disclosure, UTT had not responded to the vulnerability report and no official patch is available. Administrators should monitor the vendor's product pages and the VulDB entry for updates. If the vendor does not release a fix, consider replacing the device with a supported alternative.

Workarounds

• Segment the router onto a dedicated management network that is not reachable from user or guest VLANs.
• Block external traffic to TCP ports used by the device web UI at the perimeter firewall.
• Apply web application firewall (WAF) rules in front of the management interface to drop POST requests with oversized ssid parameters.
• For high-risk environments, decommission the UTT 750W and migrate to a vendor-supported router with an active security update cycle.

# Example firewall rule to restrict router management access to a trusted subnet
iptables -A INPUT -p tcp --dport 80 -s 10.0.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 10.0.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP