CVE-2025-14706: Sgwbox N3 Firmware RCE Vulnerability

CVE-2025-14706 Overview

A command injection vulnerability has been identified in the Shiguangwu sgwbox N3 network-attached storage (NAS) device running firmware version 2.0.25. The vulnerability exists within the /usr/sbin/http_eshell_server component, specifically in the NETREBOOT Interface functionality. An attacker can exploit this flaw to inject arbitrary operating system commands, potentially gaining complete control over the affected device.

This vulnerability is particularly concerning as it requires no authentication and can be exploited remotely over the network. The vendor was contacted about this security issue but failed to respond, leaving users without an official patch.

Critical Impact

Unauthenticated remote attackers can execute arbitrary commands on the affected sgwbox N3 device, potentially leading to complete system compromise, data theft, or use of the device in botnet operations.

Affected Products

• Shiguangwu sgwbox N3 Firmware version 2.0.25
• Shiguangwu sgwbox N3 Hardware

Discovery Timeline

• 2025-12-15 - CVE-2025-14706 published to NVD
• 2025-12-31 - Last updated in NVD database

Technical Details for CVE-2025-14706

Vulnerability Analysis

This vulnerability is classified as a command injection flaw (CWE-77) and broader injection vulnerability (CWE-74). The vulnerable component, http_eshell_server, handles HTTP requests for device management functions including the NETREBOOT interface. The application fails to properly sanitize user-supplied input before passing it to system shell commands, allowing attackers to inject malicious commands that execute with the privileges of the web server process.

The network-accessible nature of this vulnerability means that any attacker who can reach the device's management interface can potentially exploit it. Since NAS devices often contain sensitive data and may be connected to internal networks, successful exploitation could serve as a pivot point for further attacks within an organization's infrastructure.

Root Cause

The root cause of this vulnerability lies in improper input validation within the NETREBOOT interface of the http_eshell_server binary. User-controlled input is concatenated or passed directly to shell command execution functions without adequate sanitization or escaping of shell metacharacters. This allows attackers to break out of the intended command context and execute arbitrary commands.

Common patterns that lead to such vulnerabilities include using functions like system(), popen(), or backtick operators with unsanitized user input, or constructing command strings through string concatenation without proper escaping.

Attack Vector

The attack is executed remotely over the network by sending specially crafted HTTP requests to the NETREBOOT interface endpoint. An attacker would typically inject shell metacharacters (such as ;, |, &&, or backticks) followed by malicious commands into parameters processed by the vulnerable interface.

The vulnerability affects the file /usr/sbin/http_eshell_server and can be triggered without any prior authentication, making it trivial to exploit for any attacker with network access to the device. Technical details about the exploitation methodology are documented in the Notion Command Injection Analysis resource.

Detection Methods for CVE-2025-14706

Indicators of Compromise

• Unusual outbound network connections from the sgwbox N3 device to unknown IP addresses
• Unexpected processes running on the device, particularly shell interpreters spawned by http_eshell_server
• Modified system files or unauthorized user accounts created on the device
• Suspicious HTTP requests to the NETREBOOT interface containing shell metacharacters (;, |, &&, `)

Detection Strategies

• Deploy network intrusion detection systems (IDS) with rules to detect command injection patterns in HTTP traffic destined for sgwbox devices
• Monitor HTTP access logs for requests to the NETREBOOT endpoint containing suspicious characters or encoded payloads
• Implement egress filtering to alert on unexpected outbound connections from IoT/NAS devices
• Use behavioral analysis tools to detect anomalous process execution patterns on embedded devices

Monitoring Recommendations

• Isolate sgwbox N3 devices on a separate network segment with restricted access
• Enable detailed logging for all HTTP requests to the device management interface
• Monitor for any changes to critical system files or configurations on the device
• Set up alerts for new network connections initiated by the NAS device

How to Mitigate CVE-2025-14706

Immediate Actions Required

• Restrict network access to the sgwbox N3 management interface using firewall rules, limiting access to trusted administrators only
• Place the device behind a VPN or on an isolated management network segment
• Disable the NETREBOOT interface if it is not required for operational purposes
• Audit the device for signs of compromise and restore from known-good backup if necessary

Patch Information

No official patch is currently available from the vendor. According to the vulnerability disclosure, the vendor (Shiguangwu) was contacted about this security issue but did not respond. Users should monitor for firmware updates from the vendor and apply them immediately when available. Additional technical information is available via VulDB #336423.

Workarounds

• Implement strict network segmentation to isolate the vulnerable device from untrusted networks and the internet
• Deploy a web application firewall (WAF) or reverse proxy in front of the device to filter malicious requests containing command injection payloads
• If possible, disable the HTTP management interface entirely and manage the device through alternative secure methods
• Consider replacing the affected device with a NAS solution from a vendor with active security support

# Example firewall rule to restrict access to sgwbox management interface
# Only allow access from trusted management network (192.168.10.0/24)
iptables -A INPUT -p tcp --dport 80 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP