CVE-2026-3015: Utt 810g Firmware Buffer Overflow Flaw

CVE-2026-3015 Overview

A critical buffer overflow vulnerability has been identified in UTT HiPER 810G routers running firmware versions up to 1.7.7-171114. The vulnerability exists in the strcpy function within the /goform/formPolicyRouteConf endpoint. Attackers can exploit this flaw by manipulating the GroupName argument, leading to a buffer overflow condition. This vulnerability can be exploited remotely, and proof-of-concept exploit code has been publicly disclosed.

Critical Impact

Remote attackers can exploit this buffer overflow vulnerability to potentially execute arbitrary code, compromise device integrity, or cause denial of service on affected UTT HiPER 810G routers.

Affected Products

• UTT HiPER 810G Firmware up to version 1.7.7-171114
• UTT HiPER 810G Hardware version 3.0
• UTT 810G Firmware (all versions prior to patch)

Discovery Timeline

• 2026-02-23 - CVE-2026-3015 published to NVD
• 2026-02-24 - Last updated in NVD database

Technical Details for CVE-2026-3015

Vulnerability Analysis

This vulnerability stems from improper bounds checking in the firmware's policy route configuration handler. The affected function uses strcpy to copy user-supplied input from the GroupName parameter without validating the length of the input data. When an attacker submits an overly long string through this parameter, the function copies data beyond the allocated buffer boundaries, corrupting adjacent memory regions.

The vulnerability is accessible via the web management interface at /goform/formPolicyRouteConf, which handles policy-based routing configuration on the device. Since the attack can be launched remotely over the network and requires only low-privilege authentication, it presents a significant risk to organizations using these devices. The potential impact includes complete compromise of confidentiality, integrity, and availability of the affected device.

Root Cause

The root cause of CVE-2026-3015 is a classic buffer overflow vulnerability (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer). The firmware developers used the unsafe strcpy function to handle user-supplied input in the GroupName argument without implementing proper input length validation. This allows attackers to overflow the destination buffer and potentially overwrite critical memory structures such as return addresses or function pointers.

Attack Vector

The attack vector for this vulnerability is network-based, requiring remote access to the device's web management interface. An attacker with low-level authentication privileges can craft a malicious HTTP POST request to the /goform/formPolicyRouteConf endpoint containing an oversized GroupName parameter value. When processed by the vulnerable strcpy function, this triggers the buffer overflow condition.

The vulnerability mechanism works as follows: when the web form handler receives the policy route configuration request, it extracts the GroupName parameter and passes it to strcpy without bounds checking. By submitting a carefully crafted payload exceeding the buffer size, attackers can corrupt stack memory and potentially redirect execution flow. Technical details and proof-of-concept information are available in the GitHub CVE Report Repository.

Detection Methods for CVE-2026-3015

Indicators of Compromise

• Unusual HTTP POST requests to /goform/formPolicyRouteConf with abnormally long GroupName parameter values
• Unexpected device reboots or crashes potentially indicating exploitation attempts
• Anomalous outbound network connections from the router to unknown destinations
• Modified configuration files or unauthorized administrative access on affected devices

Detection Strategies

• Deploy web application firewall (WAF) rules to inspect and block HTTP requests with oversized GroupName parameters targeting /goform/formPolicyRouteConf
• Implement network intrusion detection signatures to identify buffer overflow exploitation patterns in HTTP traffic to UTT HiPER 810G devices
• Enable comprehensive logging on affected devices and forward logs to a SIEM for anomaly detection
• Monitor for unusual process behavior or memory consumption on router management interfaces

Monitoring Recommendations

• Establish baseline network traffic patterns for UTT HiPER 810G device management interfaces and alert on deviations
• Implement continuous vulnerability scanning to identify unpatched UTT devices in your environment
• Review device access logs regularly for unauthorized authentication attempts or configuration changes
• Set up alerting for any connections to known malicious infrastructure referenced in VulDB CTI ID #347375

How to Mitigate CVE-2026-3015

Immediate Actions Required

• Identify all UTT HiPER 810G devices in your network running firmware version 1.7.7-171114 or earlier
• Restrict network access to the device management interface using firewall rules to allow only trusted administrator IP addresses
• Disable remote management access if not required for business operations
• Monitor affected devices for signs of compromise while awaiting vendor patches

Patch Information

At the time of publication, no vendor patch has been officially released for this vulnerability. Organizations should monitor UTT's official channels and the VulDB entry #347375 for patch availability. The exploit has been publicly disclosed as documented in the GitHub PoC repository, increasing the urgency for mitigation measures.

Workarounds

• Implement network segmentation to isolate UTT HiPER 810G devices from untrusted network segments
• Configure access control lists (ACLs) to restrict management interface access to specific trusted IP addresses only
• Deploy a reverse proxy or WAF in front of the management interface with input validation rules limiting GroupName parameter length
• Consider temporary device replacement with alternative hardware until a patch is available if the risk is unacceptable

# Example: Restrict management interface access via iptables on upstream firewall
iptables -A FORWARD -d <UTT_DEVICE_IP> -p tcp --dport 80 -j DROP
iptables -A FORWARD -d <UTT_DEVICE_IP> -p tcp --dport 443 -j DROP
iptables -A FORWARD -s <TRUSTED_ADMIN_IP> -d <UTT_DEVICE_IP> -p tcp --dport 80 -j ACCEPT
iptables -A FORWARD -s <TRUSTED_ADMIN_IP> -d <UTT_DEVICE_IP> -p tcp --dport 443 -j ACCEPT