CVE-2026-2847: UTT HiPER 520 Firmware RCE Vulnerability

CVE-2026-2847 Overview

A critical OS command injection vulnerability has been discovered in the UTT HiPER 520 router firmware version 1.7.7-160105. The vulnerability exists within the sub_44EFB4 function of the Web Management Interface, specifically in the file /goform/formReleaseConnect. By manipulating the Isp_Name argument, an authenticated attacker with high privileges can inject arbitrary operating system commands that execute on the underlying device. This vulnerability can be exploited remotely over the network, and proof-of-concept exploit code has been publicly disclosed.

Critical Impact
Remote attackers with administrative access can achieve full system compromise through OS command injection, potentially leading to complete device takeover, network pivoting, and persistent backdoor installation on affected UTT HiPER 520 routers.

Affected Products

UTT HiPER 520 Firmware version 1.7.7-160105
UTT 520 Hardware version 3.0
UTT 520 Firmware (all variants running vulnerable firmware version)

Discovery Timeline

2026-02-20 - CVE-2026-2847 published to NVD
2026-02-24 - Last updated in NVD database

Technical Details for CVE-2026-2847

Vulnerability Analysis

This vulnerability represents a classic OS command injection flaw (CWE-77: Improper Neutralization of Special Elements used in a Command) within the UTT HiPER 520 router's web management interface. The affected function sub_44EFB4 processes user-supplied input from the Isp_Name parameter without adequate sanitization or validation before passing it to a system command execution context.

The vulnerability is accessible through a network-based attack vector and requires the attacker to have high-level privileges (administrative access) on the device. No user interaction is required for exploitation, making automated attacks feasible once authentication credentials are obtained.

Successful exploitation allows an attacker to achieve complete confidentiality, integrity, and availability impact on the vulnerable device. The attack complexity is low, meaning no special conditions or circumstances need to exist for the vulnerability to be exploited.

Root Cause

The root cause of CVE-2026-2847 lies in the improper handling of user-supplied input within the sub_44EFB4 function. The Isp_Name parameter value is incorporated into an OS command without proper sanitization, escaping, or parameterization. This allows attackers to break out of the intended command context and inject arbitrary shell commands that execute with the privileges of the web server process.

The web management interface at /goform/formReleaseConnect fails to implement input validation checks that would prevent command metacharacters (such as ;, |, &, $(), and backticks) from being processed as command separators or command substitution operators.

Attack Vector

The attack vector is network-based, targeting the HTTP/HTTPS web management interface of the UTT HiPER 520 router. An attacker who has obtained administrative credentials (through credential theft, default credentials, or brute force attacks) can craft a malicious HTTP request to the /goform/formReleaseConnect endpoint.

By including command injection payloads within the Isp_Name parameter, the attacker can execute arbitrary commands on the router's operating system. Common attack scenarios include:

Establishing reverse shells for persistent remote access
Modifying router configuration to redirect traffic
Installing malware or backdoors on the device
Using the compromised router as a pivot point for lateral movement within the network
Exfiltrating sensitive network traffic or configuration data

Technical details and proof-of-concept information are available in the GitHub PoC Repository and VulDB Case Study.

Detection Methods for CVE-2026-2847

Indicators of Compromise

Unusual HTTP POST requests to /goform/formReleaseConnect containing shell metacharacters in the Isp_Name parameter
Unexpected outbound network connections from the router to external IP addresses
Anomalous processes spawned by the web server process on the router
Modifications to router configuration files or startup scripts that were not authorized
Evidence of reverse shell connections or netcat listeners on the device

Detection Strategies

Monitor web server logs for requests to /goform/formReleaseConnect containing suspicious characters such as ;, |, &, $(, or backticks in POST parameters
Implement network intrusion detection rules to identify command injection patterns in HTTP traffic destined for UTT HiPER 520 management interfaces
Deploy behavioral analysis to detect unusual command execution patterns or process spawning on network devices
Audit authentication logs for failed or suspicious login attempts preceding exploitation activity

Monitoring Recommendations

Enable comprehensive logging on the UTT HiPER 520 web management interface and forward logs to a central SIEM for analysis
Establish baseline network behavior for router management traffic and alert on deviations
Implement egress filtering to detect unauthorized outbound connections from network infrastructure devices
Regularly review router configurations for unauthorized changes that may indicate compromise

How to Mitigate CVE-2026-2847

Immediate Actions Required

Restrict access to the web management interface by implementing IP-based access control lists limiting administrative access to trusted management networks only
Change default administrative credentials and implement strong, unique passwords for all administrative accounts
Disable remote management access over untrusted networks (such as WAN interfaces) if not operationally required
Monitor for exploitation attempts using the detection strategies outlined above
Consider taking vulnerable devices offline or isolating them until a patch is available

Patch Information

At the time of publication, no official vendor patch has been released for this vulnerability. Organizations should monitor UTT's official channels and the VulDB entry for updates on patch availability. Contact UTT support directly to inquire about firmware updates that address CVE-2026-2847.

Workarounds

Implement network segmentation to isolate the management interface from untrusted network segments
Deploy a web application firewall (WAF) or reverse proxy in front of the management interface to filter malicious input patterns
Use VPN connections for remote administration rather than exposing the web interface directly
Disable the web management interface entirely and use alternative management methods (serial console) if available and operationally feasible

bash

# Example: Restrict management interface access via firewall rules
# Block external access to the management interface 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

# Only allow management access from specific trusted hosts
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