CVE-2026-2071: UTT 进取 520W Buffer Overflow Vulnerability

CVE-2026-2071 Overview

A buffer overflow vulnerability has been identified in the UTT 进取 520W router firmware version 1.7.7-180627. The vulnerability exists within the strcpy function implementation in the file /goform/formP2PLimitConfig. An attacker can exploit this flaw by manipulating the except argument, causing a buffer overflow condition. This vulnerability is remotely exploitable and could allow attackers to compromise affected network devices.

Critical Impact

Remote attackers can exploit this buffer overflow vulnerability to potentially execute arbitrary code or cause denial of service on vulnerable UTT 进取 520W routers. The exploit has been publicly disclosed, increasing the risk of active exploitation.

Affected Products

• UTT 进取 520W Router Firmware version 1.7.7-180627

Discovery Timeline

• 2026-02-07 - CVE-2026-2071 published to NVD
• 2026-02-09 - Last updated in NVD database

Technical Details for CVE-2026-2071

Vulnerability Analysis

This vulnerability is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The flaw originates from unsafe use of the strcpy function when processing user-controlled input in the P2P limit configuration form handler. When the except parameter is manipulated with crafted input, the function copies data into a fixed-size buffer without proper bounds checking, leading to a classic stack-based buffer overflow condition.

The vulnerability is network-accessible without user interaction, meaning attackers can target vulnerable devices remotely. Since the affected component handles router configuration, successful exploitation could grant attackers complete control over the network device, potentially allowing them to intercept traffic, modify routing tables, or use the compromised device as a pivot point for further attacks.

Root Cause

The root cause of this vulnerability is the unsafe use of the strcpy function to copy user-supplied input from the except parameter into a fixed-size buffer without validating the input length. The strcpy function does not perform bounds checking, making it inherently dangerous when used with untrusted input. Modern secure coding practices recommend using safer alternatives such as strncpy or strlcpy with explicit length limits to prevent such overflow conditions.

Attack Vector

The attack can be conducted remotely over the network by sending a specially crafted HTTP request to the /goform/formP2PLimitConfig endpoint on vulnerable UTT 进取 520W routers. The attacker would need to provide an oversized value in the except parameter to trigger the buffer overflow. Depending on the router's memory layout and protection mechanisms, this could lead to:

1. Denial of service through crashing the web management interface
2. Remote code execution if the attacker can control the instruction pointer
3. Information disclosure if memory contents are leaked

The vulnerability requires low privileges (authenticated access to the web interface) but can be exploited remotely without user interaction. For detailed technical information about the vulnerability, refer to the GitHub CVE Documentation.

Detection Methods for CVE-2026-2071

Indicators of Compromise

• Unusual HTTP POST requests to /goform/formP2PLimitConfig with abnormally large except parameter values
• Router crashes or unexpected reboots coinciding with web interface access
• Anomalous outbound connections from the router to unknown IP addresses
• Modified router configurations or unexpected admin account changes

Detection Strategies

• Monitor HTTP traffic to UTT routers for POST requests containing oversized parameters in the formP2PLimitConfig endpoint
• Implement network intrusion detection rules to identify buffer overflow payload patterns targeting embedded devices
• Deploy SentinelOne Singularity for network device monitoring to detect exploitation attempts and anomalous behavior
• Regularly audit router configurations for unauthorized changes that may indicate successful compromise

Monitoring Recommendations

• Enable logging on UTT routers and forward logs to a centralized SIEM for analysis
• Monitor for repeated authentication attempts followed by requests to the vulnerable endpoint
• Set up alerts for unusual traffic patterns originating from network infrastructure devices
• Implement network segmentation to limit exposure of management interfaces

How to Mitigate CVE-2026-2071

Immediate Actions Required

• Restrict access to the router's web management interface to trusted IP addresses only
• Place vulnerable UTT 进取 520W routers behind a firewall that blocks external access to management ports
• Disable remote management if not required and use local console access for configuration changes
• Monitor affected devices for signs of compromise and prepare for replacement if no patch becomes available

Patch Information

The vendor (UTT) was contacted about this vulnerability but did not respond. As of the last NVD update on 2026-02-09, no official patch has been released. Organizations using affected devices should implement the recommended workarounds and consider migrating to alternative router solutions from vendors with active security support.

For more information, see the VulDB advisory which tracks this vulnerability.

Workarounds

• Implement strict firewall rules to block external access to the router management interface on ports 80 and 443
• Configure network ACLs to allow management access only from specific trusted administrator IP addresses
• Consider deploying a reverse proxy with input validation in front of the management interface to filter malicious requests
• Replace vulnerable devices with supported alternatives if the vendor continues to be unresponsive

# Example firewall rules to restrict management access (iptables)
# Block external access to router management 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