CVE-2026-31061: UTT Aggressive HiPER 810G DoS Vulnerability

CVE-2026-31061 Overview

A buffer overflow vulnerability has been identified in the UTT Aggressive HiPER 810G v3v1.7.7-171114 router firmware. The vulnerability exists in the timestart parameter of the ConfigAdvideo function, which fails to properly validate input length before copying data into a fixed-size buffer. This flaw allows attackers with adjacent network access and administrative privileges to cause a Denial of Service (DoS) condition by sending specially crafted input to the affected parameter.

Critical Impact

Successful exploitation of this buffer overflow vulnerability can crash the router device, disrupting network connectivity for all connected users and potentially requiring a manual device restart to restore service.

Affected Products

• UTT Aggressive HiPER 810G v3v1.7.7-171114

Discovery Timeline

• 2026-04-06 - CVE-2026-31061 published to NVD
• 2026-04-07 - Last updated in NVD database

Technical Details for CVE-2026-31061

Vulnerability Analysis

This buffer overflow vulnerability (CWE-120: Buffer Copy without Checking Size of Input) occurs when the ConfigAdvideo function processes the timestart parameter without adequate bounds checking. When user-supplied data exceeds the allocated buffer size, memory corruption occurs, leading to application instability and denial of service.

The vulnerability requires adjacent network access, meaning the attacker must be on the same network segment as the target device. Additionally, high privileges (administrative access) are required to reach the vulnerable function, which somewhat limits the attack surface. However, in environments where administrative credentials may be weak or shared, this vulnerability poses a significant risk to network availability.

Root Cause

The root cause is a classic buffer overflow scenario where the ConfigAdvideo function accepts input through the timestart parameter without validating the input length against the destination buffer's capacity. When oversized input is provided, it overwrites adjacent memory regions, corrupting the application's execution state and causing the device to crash or become unresponsive.

Attack Vector

The attack vector requires adjacent network positioning, meaning the attacker must have network-level access to communicate with the router's management interface. The attack flow typically involves:

1. Gaining access to the router's administrative interface (requires authentication)
2. Navigating to or directly accessing the ConfigAdvideo function endpoint
3. Submitting a crafted request with an oversized value in the timestart parameter
4. The overflow corrupts memory, causing the device to crash

The vulnerability is documented in a GitHub Exploit Documentation repository. Readers can refer to this resource for additional technical details about the exploitation mechanism.

Detection Methods for CVE-2026-31061

Indicators of Compromise

• Unexpected router reboots or crashes without apparent cause
• Abnormally large or malformed HTTP requests to the router's web management interface targeting ConfigAdvideo
• Authentication logs showing administrative access followed by immediate device failures
• Network traffic containing unusually long strings in the timestart parameter

Detection Strategies

• Implement network intrusion detection rules to identify oversized parameter values in HTTP requests to the router management interface
• Monitor for repeated authentication attempts to the router's administrative interface from unexpected network segments
• Configure logging on the router (if supported) to capture access to configuration functions
• Deploy network monitoring to detect unusual traffic patterns targeting the device's management ports

Monitoring Recommendations

• Enable and regularly review device access logs for administrative interface activity
• Set up alerting for router availability to quickly detect DoS conditions
• Monitor adjacent network segments for unauthorized devices that could launch attacks
• Implement baseline monitoring for normal router behavior to detect anomalies

How to Mitigate CVE-2026-31061

Immediate Actions Required

• Restrict access to the router's administrative interface to trusted IP addresses only
• Ensure strong, unique administrative credentials are in use
• Segment the network to limit adjacent network access to the management interface
• Consider placing the router behind a firewall that can filter malicious requests

Patch Information

No official vendor patch information is currently available for this vulnerability. Organizations should monitor UTT's official channels for firmware updates that address this issue. In the absence of an official patch, implementing the workarounds below is strongly recommended.

Workarounds

• Implement access control lists (ACLs) to restrict management interface access to specific trusted hosts
• Disable remote management access if not required for operations
• Use a separate, isolated management VLAN for administrative access to network devices
• Deploy a web application firewall (WAF) or reverse proxy in front of the management interface to filter oversized parameters

# Example: Restrict management interface access via firewall rules
# Block external access to management port (example for iptables)
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP