CVE-2026-31066: UTT Aggressive HiPER 810G DoS Vulnerability

CVE-2026-31066 Overview

A buffer overflow vulnerability has been identified in UTT Aggressive HiPER 810G v3v1.7.7-171114, specifically in the selDateType parameter of the formTaskEdit function. This vulnerability allows attackers with adjacent network access and high privileges to cause a Denial of Service (DoS) condition via crafted input.

Critical Impact

Authenticated attackers on adjacent networks can exploit this buffer overflow to crash affected UTT HiPER router devices, disrupting network connectivity and services.

Affected Products

• UTT Aggressive HiPER 810G v3v1.7.7-171114

Discovery Timeline

• April 6, 2026 - CVE-2026-31066 published to NVD
• April 7, 2026 - Last updated in NVD database

Technical Details for CVE-2026-31066

Vulnerability Analysis

This vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input), a classic buffer overflow condition. The flaw exists within the formTaskEdit function, which handles task editing operations on the router's management interface. When processing the selDateType parameter, the function fails to properly validate the length of user-supplied input before copying it to a fixed-size buffer.

The attack requires adjacent network access, meaning the attacker must be on the same network segment as the target device. Additionally, high-level administrative privileges are required to access the vulnerable function, which somewhat limits the exploitability. However, once these conditions are met, exploitation is straightforward with low attack complexity.

The impact is limited to availability, with no confidentiality or integrity implications. A successful exploit causes the device to crash or become unresponsive, resulting in a Denial of Service condition that affects network connectivity for users relying on the router.

Root Cause

The root cause is improper input validation in the formTaskEdit function. The function accepts the selDateType parameter without adequately checking its size before performing a buffer copy operation. This allows an attacker to supply an oversized input that exceeds the destination buffer's capacity, corrupting adjacent memory and causing the application to crash.

Attack Vector

The attack is executed from an adjacent network position, requiring the attacker to have access to the same local network segment as the target UTT HiPER router. The attacker must authenticate with high-level administrative credentials to access the vulnerable formTaskEdit function. Once authenticated, the attacker crafts a malicious request containing an oversized selDateType parameter value that triggers the buffer overflow when processed by the router's web management interface.

The vulnerability mechanism involves the following attack flow:

1. Attacker gains access to the adjacent network where the UTT HiPER router is deployed
2. Attacker authenticates to the router's management interface with administrative credentials
3. Attacker submits a crafted request to the formTaskEdit endpoint with an oversized selDateType parameter
4. The router processes the input without proper bounds checking, causing a buffer overflow
5. Memory corruption occurs, leading to device crash and Denial of Service

For additional technical details, refer to the GitHub Vulnerability Document.

Detection Methods for CVE-2026-31066

Indicators of Compromise

• Unexpected router reboots or crashes, particularly after administrative interface access
• Abnormally large HTTP POST requests to the router's management interface targeting task editing functions
• Authentication logs showing administrative access followed by device instability

Detection Strategies

• Monitor network traffic for unusually large parameter values in requests to the router's web management interface
• Implement intrusion detection rules to flag requests to formTaskEdit endpoints with oversized selDateType parameters
• Review router logs for repeated crashes or restarts that may indicate exploitation attempts

Monitoring Recommendations

• Enable comprehensive logging on UTT HiPER router devices to capture administrative actions
• Implement network segmentation monitoring to detect unauthorized access to management interfaces from adjacent networks
• Set up alerts for router availability to quickly identify potential DoS attacks

How to Mitigate CVE-2026-31066

Immediate Actions Required

• Restrict administrative access to the router's management interface to trusted IP addresses only
• Implement strong authentication mechanisms and change default administrative credentials
• Isolate the router's management interface on a dedicated management VLAN inaccessible from general user networks
• Monitor for firmware updates from UTT addressing this vulnerability

Patch Information

No official patch information is currently available from the vendor. Organizations should monitor UTT's official channels for security updates addressing this buffer overflow vulnerability in the HiPER 810G firmware. Contact UTT support for guidance on remediation options.

Workarounds

• Disable remote management access to the router if not required for operations
• Implement network access controls to limit which devices can reach the router's administrative interface
• Deploy a web application firewall or reverse proxy in front of the management interface to filter oversized input parameters
• Consider replacing affected devices with alternative products if no patch becomes available

Network administrators should implement firewall rules to restrict access to the management interface:

# Example iptables rules to restrict management access
# Allow management access only from trusted admin workstation
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.100 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.100 -j ACCEPT

# Block all other access to management ports
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP