CVE-2026-3016: UTT 810G Firmware Buffer Overflow Flaw

CVE-2026-3016 Overview

A buffer overflow vulnerability has been identified in UTT HiPER 810G devices running firmware versions up to and including 1.7.7-171114. The vulnerability exists in the strcpy function within the file /goform/formP2PLimitConfig, where improper handling of the except argument allows an attacker to trigger a buffer overflow condition. This vulnerability can be exploited remotely over the network by authenticated attackers, potentially leading to arbitrary code execution or denial of service on affected devices.

Critical Impact

Remote exploitation allows attackers to potentially gain complete control of the network router, compromising all traffic passing through the device and enabling further network intrusion.

Affected Products

• UTT HiPER 810G Firmware versions up to 1.7.7-171114
• UTT 810G Hardware version 3.0

Discovery Timeline

• 2026-02-23 - CVE-2026-3016 published to NVD
• 2026-02-24 - Last updated in NVD database

Technical Details for CVE-2026-3016

Vulnerability Analysis

This vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The core issue stems from the use of the unsafe strcpy function to process user-supplied input in the P2P limit configuration handler. The strcpy function does not perform bounds checking, which allows an attacker to supply an oversized except argument that exceeds the allocated buffer size. When this occurs, adjacent memory regions are overwritten, potentially corrupting critical program data, function pointers, or return addresses.

The vulnerability is accessible via the network, requires low attack complexity, and can be exploited by attackers with low privileges. While no user interaction is required for exploitation, authenticated access to the device's web interface is necessary. A successful exploit could result in complete compromise of confidentiality, integrity, and availability of the affected device.

Root Cause

The root cause of this vulnerability is the improper use of the strcpy function without adequate input validation or length checking. The /goform/formP2PLimitConfig handler directly copies user-supplied data from the except parameter into a fixed-size buffer without verifying that the input length does not exceed the buffer capacity. This classic buffer overflow pattern allows attackers to write beyond the bounds of the intended memory region.

Attack Vector

The attack vector is network-based, targeting the web management interface of the UTT HiPER 810G router. An attacker with valid authentication credentials can craft a malicious HTTP POST request to the /goform/formP2PLimitConfig endpoint, supplying an excessively long string in the except parameter.

The exploitation mechanism involves:

1. Authenticating to the router's web management interface
2. Sending a crafted POST request to /goform/formP2PLimitConfig
3. Including an oversized except parameter value designed to overflow the target buffer
4. Overwriting critical memory structures such as return addresses or function pointers
5. Achieving arbitrary code execution or causing a denial of service condition

Proof-of-concept documentation for this vulnerability is publicly available. For technical details, refer to the GitHub CVE Report and GitHub PoC Documentation.

Detection Methods for CVE-2026-3016

Indicators of Compromise

• Unusual HTTP POST requests to /goform/formP2PLimitConfig with abnormally large parameter values
• Router crashes, reboots, or unexplained service disruptions
• Unexpected changes to P2P limit configuration settings
• Memory corruption errors or segmentation faults in router logs

Detection Strategies

• Implement intrusion detection rules to flag HTTP requests to /goform/formP2PLimitConfig containing oversized except parameters
• Monitor for anomalous traffic patterns targeting the router's web management interface
• Deploy network-based anomaly detection to identify buffer overflow exploitation attempts
• Review access logs for unauthorized or unusual authentication attempts to the management interface

Monitoring Recommendations

• Enable comprehensive logging on the UTT HiPER 810G management interface if supported
• Implement network traffic analysis to detect malformed HTTP requests targeting router endpoints
• Set up alerts for device reboots or service interruptions that may indicate exploitation attempts
• Monitor for unexpected outbound connections from the router that could indicate compromise

How to Mitigate CVE-2026-3016

Immediate Actions Required

• Restrict access to the router's web management interface to trusted IP addresses only
• Implement strong authentication credentials and change default passwords
• Consider disabling remote management access if not required
• Place the management interface behind a VPN or additional firewall controls
• Monitor for firmware updates from UTT that address this vulnerability

Patch Information

No vendor security patch has been confirmed at this time. Organizations should monitor UTT's official channels and security advisories for firmware updates that address CVE-2026-3016. Additional vulnerability information is tracked at VulDB #347376.

Workarounds

• Restrict management interface access to localhost or specific trusted internal IP addresses using firewall rules
• Disable the web management interface entirely if it is not required for operations
• Implement network segmentation to isolate affected devices from untrusted networks
• Deploy a web application firewall (WAF) in front of the management interface to filter malicious requests

# Example: Restrict management access using iptables on upstream firewall
# Block external access to router management port (typically 80 or 443)
iptables -A FORWARD -d <ROUTER_IP> -p tcp --dport 80 -j DROP
iptables -A FORWARD -d <ROUTER_IP> -p tcp --dport 443 -j DROP

# Allow management access only from trusted admin workstation
iptables -I FORWARD -s <ADMIN_IP> -d <ROUTER_IP> -p tcp --dport 80 -j ACCEPT
iptables -I FORWARD -s <ADMIN_IP> -d <ROUTER_IP> -p tcp --dport 443 -j ACCEPT