CVE-2026-4487: UTT HiPER 1200GW Buffer Overflow Flaw

CVE-2026-4487 Overview

A buffer overflow vulnerability has been identified in UTT HiPER 1200GW router firmware up to version 2.5.3-170306. This vulnerability impacts the strcpy function within the /goform/websHostFilter endpoint, allowing remote attackers to overflow memory buffers. The exploit has been publicly disclosed and may be actively utilized by threat actors targeting network infrastructure devices.

Critical Impact

Remote attackers can exploit this buffer overflow vulnerability over the network to potentially execute arbitrary code, crash the device, or gain unauthorized access to the router's administrative functions.

Affected Products

• UTT HiPER 1200GW firmware versions up to 2.5.3-170306

Discovery Timeline

• 2026-03-20 - CVE-2026-4487 published to NVD
• 2026-03-24 - Last updated in NVD database

Technical Details for CVE-2026-4487

Vulnerability Analysis

This vulnerability is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The vulnerability exists in the web management interface of the UTT HiPER 1200GW router, specifically in the host filtering functionality accessed via the /goform/websHostFilter endpoint.

The unsafe use of the strcpy function without proper bounds checking allows an attacker to submit crafted input that exceeds the allocated buffer size. Since strcpy does not validate the length of the source string before copying, excessively long input overwrites adjacent memory regions, leading to memory corruption. This can result in denial of service, arbitrary code execution, or complete device compromise.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring physical access to the device. However, authentication may be required to access the vulnerable endpoint, which provides some level of access control.

Root Cause

The root cause of this vulnerability is the use of the unsafe strcpy function in the /goform/websHostFilter handler code. The function copies user-supplied input into a fixed-size buffer without validating that the input length does not exceed the buffer's capacity. This is a classic example of improper input validation leading to a buffer overflow condition. Secure alternatives such as strncpy or snprintf with explicit length limits should have been used to prevent this vulnerability.

Attack Vector

The attack vector is network-based, allowing remote exploitation. An authenticated or unauthenticated attacker (depending on the endpoint's access controls) can send a specially crafted HTTP request to the /goform/websHostFilter endpoint containing an oversized payload in one of the parameters processed by the vulnerable strcpy call.

The attacker constructs a malicious request with input data exceeding the expected buffer size. When the router processes this request, the strcpy function copies the oversized input into a stack or heap buffer, overwriting adjacent memory. Depending on the memory layout, this could allow the attacker to overwrite return addresses, function pointers, or other critical data structures to redirect execution flow or cause a device crash.

Technical details and proof-of-concept information are available in the GitHub HiPER Documentation.

Detection Methods for CVE-2026-4487

Indicators of Compromise

• HTTP POST requests to /goform/websHostFilter containing abnormally long parameter values
• Unexpected router reboots or crashes that may indicate exploitation attempts
• Unusual network traffic patterns originating from or directed at the router management interface
• Log entries showing malformed requests to the web management interface

Detection Strategies

• Monitor HTTP traffic to router management interfaces for requests containing oversized payloads or buffer overflow patterns
• Deploy network intrusion detection systems (NIDS) with signatures targeting buffer overflow attacks against embedded devices
• Review router access logs for repeated requests to /goform/websHostFilter from suspicious IP addresses
• Implement web application firewall (WAF) rules to block requests exceeding expected parameter lengths

Monitoring Recommendations

• Enable and regularly review router access logs for suspicious activity on the web management interface
• Configure network monitoring to alert on unusual traffic volumes or patterns to router management ports
• Establish baseline behavior for router performance and monitor for anomalies that may indicate exploitation
• Segment router management interfaces to dedicated VLANs with strict access controls

How to Mitigate CVE-2026-4487

Immediate Actions Required

• Restrict network access to the router's web management interface to trusted IP addresses only
• Disable remote management if not required, limiting access to local network only
• Implement firewall rules to block external access to the /goform/ endpoints
• Monitor the affected devices for signs of compromise while awaiting vendor patches

Patch Information

No official patch information is currently available from UTT. Organizations should monitor vendor communications and the VulDB entry for updates on patch availability. Contact UTT support directly to inquire about firmware updates that address this vulnerability.

Workarounds

• Disable the web management interface entirely and use alternative management methods such as CLI access via serial console
• Place affected routers behind a firewall that filters malicious requests and blocks access to the vulnerable endpoint
• Implement network access control lists (ACLs) to limit which hosts can communicate with the router management interface
• Consider replacing vulnerable devices with alternative network equipment if patches are not made available in a timely manner

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