CVE-2026-31063: UTT HiPER 1200GW Buffer Overflow DoS Flaw

CVE-2026-31063 Overview

A buffer overflow vulnerability has been identified in the UTT Aggressive HiPER 1200GW v2.5.3-170306 router firmware. The vulnerability exists in the pools parameter of the formArpBindConfig function, allowing attackers to cause a Denial of Service (DoS) condition through crafted input. This vulnerability requires adjacent network access and high privileges to exploit, limiting its attack surface but still posing a risk in enterprise network environments where these devices are deployed.

Critical Impact

Attackers with administrative access on an adjacent network can cause device unavailability through a buffer overflow in the ARP binding configuration function, potentially disrupting network services.

Affected Products

• UTT Aggressive HiPER 1200GW v2.5.3-170306

Discovery Timeline

• 2026-04-06 - CVE-2026-31063 published to NVD
• 2026-04-07 - Last updated in NVD database

Technical Details for CVE-2026-31063

Vulnerability Analysis

This vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input), commonly known as a classic buffer overflow. The formArpBindConfig function in the UTT Aggressive HiPER 1200GW router firmware fails to properly validate the length of user-supplied data in the pools parameter before copying it to a fixed-size buffer in memory.

When an attacker provides an oversized input to this parameter, the function copies the data beyond the allocated buffer boundaries, corrupting adjacent memory structures. This memory corruption leads to device instability and ultimately results in a Denial of Service condition. The attack requires the attacker to be on an adjacent network segment and possess high-level (administrative) privileges, which limits the exploitability but does not eliminate the risk in managed network environments.

Root Cause

The root cause of this vulnerability is the absence of proper bounds checking in the formArpBindConfig function when processing the pools parameter. The function copies user input directly into a fixed-size stack or heap buffer without verifying that the input length does not exceed the buffer's capacity. This classic buffer overflow pattern is a result of using unsafe string handling functions or improper implementation of input length validation.

Attack Vector

The attack vector for CVE-2026-31063 requires adjacent network access, meaning the attacker must be on the same network segment as the vulnerable device. Additionally, high privileges (administrative access) are required to access the formArpBindConfig function. The attacker can exploit this vulnerability by sending a specially crafted request with an oversized pools parameter value to the device's management interface. Upon processing the malicious input, the buffer overflow triggers memory corruption, causing the device to crash or become unresponsive.

The vulnerability mechanism involves submitting an excessively long string as the pools parameter value to the ARP binding configuration endpoint. When the formArpBindConfig function processes this input without proper bounds checking, the overflow corrupts adjacent memory, leading to device instability. Technical details and proof-of-concept information can be found in the GitHub PoC Repository.

Detection Methods for CVE-2026-31063

Indicators of Compromise

• Unexpected device reboots or crashes of UTT Aggressive HiPER 1200GW routers
• Large or abnormal HTTP POST requests to the device's management interface containing oversized parameter values
• Error logs indicating memory corruption or buffer overflow conditions
• Network connectivity disruptions following administrative interface access attempts

Detection Strategies

• Monitor network traffic for unusually large HTTP requests targeting the router's management interface
• Implement intrusion detection rules to flag requests to the formArpBindConfig endpoint with abnormally long pools parameter values
• Deploy network behavior analysis to detect patterns consistent with DoS attacks against network infrastructure devices
• Configure logging on network devices to capture administrative access attempts and configuration changes

Monitoring Recommendations

• Enable comprehensive logging on UTT Aggressive HiPER 1200GW devices to capture all administrative actions
• Implement network monitoring solutions to track device availability and detect unexpected outages
• Set up alerts for multiple failed authentication attempts or suspicious administrative activity
• Regularly review device logs for anomalous configuration change requests

How to Mitigate CVE-2026-31063

Immediate Actions Required

• Restrict administrative access to the UTT Aggressive HiPER 1200GW management interface to trusted IP addresses only
• Implement network segmentation to limit adjacent network access to critical infrastructure devices
• Review and limit the number of accounts with administrative privileges on affected devices
• Consider temporarily disabling web-based management interfaces if not actively required

Patch Information

At the time of publication, no vendor patch has been publicly announced for this vulnerability. Organizations should monitor UTT's official channels for security updates. The external reference available at the GitHub PoC Repository provides additional technical details about the vulnerability.

Workarounds

• Implement access control lists (ACLs) to restrict management interface access to specific trusted IP addresses
• Place the router's management interface on a separate, isolated VLAN accessible only to authorized administrators
• Deploy a web application firewall (WAF) or reverse proxy in front of the management interface to filter malicious requests
• Consider replacing affected devices with alternative products if the vendor does not provide a timely patch

# Example ACL configuration to restrict management access
# Limit administrative access to specific trusted networks
# Note: Actual commands may vary based on device CLI
access-list 100 permit ip 192.168.1.0 0.0.0.255 host 10.0.0.1
access-list 100 deny ip any host 10.0.0.1