CVE-2026-7420: UTT HiPER 1250GW Buffer Overflow Flaw

CVE-2026-7420 Overview

A buffer overflow vulnerability has been discovered in UTT HiPER 1250GW wireless routers up to version 3.2.7-210907-180535. The vulnerability exists in the strcpy function within the file route/goform/ConfigAdvideo, where improper handling of the Profile argument leads to a memory corruption condition. This vulnerability can be exploited remotely by authenticated attackers, potentially allowing complete compromise of the affected device.

Critical Impact

Remote attackers with low-level privileges can exploit this buffer overflow to achieve arbitrary code execution on affected UTT HiPER 1250GW routers, potentially gaining full control over network infrastructure devices.

Affected Products

• UTT HiPER 1250GW firmware version 3.2.7-210907-180535 and earlier
• UTT HiPER 1250GW wireless router devices

Discovery Timeline

• 2026-04-29 - CVE-2026-7420 published to NVD
• 2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-7420

Vulnerability Analysis

This vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The flaw resides in the web management interface of the UTT HiPER 1250GW router, specifically within the ConfigAdvideo form handler located at route/goform/ConfigAdvideo. The vulnerable code uses the strcpy function to copy user-supplied data from the Profile parameter without proper bounds checking.

When an attacker provides an oversized Profile argument value, the strcpy function copies data beyond the allocated buffer boundaries, corrupting adjacent memory regions. This can overwrite critical program control structures such as return addresses or function pointers on the stack.

The exploit has been publicly disclosed and released, increasing the risk of active exploitation in the wild.

Root Cause

The root cause is the use of the unsafe strcpy function to handle user-controlled input without implementing proper length validation. The strcpy function does not perform bounds checking, copying data until a null terminator is encountered regardless of the destination buffer size. When the Profile argument exceeds the expected buffer length, memory corruption occurs.

Attack Vector

The attack is network-based and can be executed remotely against the router's web management interface. An attacker with low-level authenticated access to the device can craft a malicious HTTP request to the /goform/ConfigAdvideo endpoint with an oversized Profile parameter. The attack does not require user interaction beyond the initial authentication.

The exploitation process involves:

1. Authenticating to the router's web management interface
2. Sending a crafted HTTP POST request to /goform/ConfigAdvideo
3. Including an oversized Profile parameter value to trigger the buffer overflow
4. Achieving arbitrary code execution or denial of service on the target device

Technical details and proof-of-concept information are available in the GitHub IoT Vulnerability Report.

Detection Methods for CVE-2026-7420

Indicators of Compromise

• Anomalous HTTP POST requests to /goform/ConfigAdvideo with unusually large Profile parameter values
• Unexpected router crashes or reboots following web interface access
• Suspicious outbound connections originating from the router device
• Unauthorized configuration changes on the affected device

Detection Strategies

• Monitor HTTP traffic to router management interfaces for requests containing oversized parameters targeting the /goform/ConfigAdvideo endpoint
• Implement network intrusion detection rules to identify buffer overflow attack patterns against UTT HiPER devices
• Review router logs for repeated crashes or service restarts that may indicate exploitation attempts

Monitoring Recommendations

• Deploy network segmentation to isolate router management interfaces from untrusted network segments
• Enable logging on affected devices and forward logs to a centralized SIEM for analysis
• Monitor for unusual authentication patterns or brute-force attempts against router web interfaces

How to Mitigate CVE-2026-7420

Immediate Actions Required

• Restrict access to the router's web management interface to trusted IP addresses only
• Disable remote management features if not required for operations
• Implement strong authentication credentials for all router administrative accounts
• Deploy network access controls to prevent unauthorized access to the management interface

Patch Information

No vendor patch information is currently available in the CVE data. Organizations should monitor UTT for security advisories and firmware updates. Additional vulnerability details can be found at VulDB Vulnerability #360157.

Workarounds

• Disable the web management interface entirely if not operationally required
• Implement firewall rules to block external access to the router management ports
• Use VPN or jump hosts for administrative access to reduce attack surface
• Consider replacing vulnerable devices with alternatives that have better security support

# Example firewall rules to restrict management interface access
# Block external access to web management port
iptables -A INPUT -p tcp --dport 80 -s ! 192.168.1.0/24 -j DROP
iptables -A INPUT -p tcp --dport 443 -s ! 192.168.1.0/24 -j DROP

# Allow management access only from specific 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