CVE-2017-20236 Overview
CVE-2017-20236 is a command injection vulnerability affecting ProSoft Technology ICX35-HWC cellular gateways running firmware versions 1.3 and prior. The vulnerability exists in the web user interface due to insufficient input validation, allowing remote attackers to inject and execute arbitrary system commands. Successful exploitation can lead to complete device compromise with root-level privileges.
Critical Impact
Remote attackers can gain root access to affected cellular gateways without authentication, enabling full device takeover and potential lateral movement within industrial networks.
Affected Products
- ProSoft Technology ICX35-HWC firmware version 1.3
- ProSoft Technology ICX35-HWC firmware versions prior to 1.3
Discovery Timeline
- 2026-04-03 - CVE CVE-2017-20236 published to NVD
- 2026-04-07 - Last updated in NVD database
Technical Details for CVE-2017-20236
Vulnerability Analysis
This vulnerability is classified as CWE-78 (Improper Neutralization of Special Elements used in an OS Command), commonly known as OS Command Injection. The ProSoft Technology ICX35-HWC cellular gateway contains a web-based management interface that fails to properly validate and sanitize user-supplied input before passing it to system shell commands.
The vulnerable web interface accepts user input through various form fields and parameters. When this input is processed by the backend application, it is incorporated into system commands without adequate sanitization. An attacker can craft malicious input containing shell metacharacters and command sequences that break out of the intended command context, allowing execution of arbitrary commands with the privileges of the web server process—typically root on embedded devices like industrial gateways.
Root Cause
The root cause of this vulnerability is improper input validation in the web user interface. The application fails to sanitize special characters and shell metacharacters from user-supplied input before incorporating it into operating system commands. This allows attackers to inject additional commands by using characters such as semicolons (;), pipes (|), backticks, or command substitution syntax ($()).
Attack Vector
The attack vector is network-based, requiring no authentication or user interaction. An attacker with network access to the ICX35-HWC web interface can submit specially crafted HTTP requests containing malicious payloads in form fields or URL parameters. These payloads are designed to escape the intended command context and inject arbitrary system commands.
Once the malicious input reaches the vulnerable code path, the injected commands execute with elevated privileges, typically root on embedded systems. This provides the attacker with complete control over the device, enabling actions such as:
- Modifying device configurations
- Intercepting or manipulating network traffic
- Installing persistent backdoors
- Using the compromised device as a pivot point for further network attacks
The vulnerability can be exploited by crafting HTTP requests with command injection payloads in vulnerable input fields. For detailed technical information, refer to the Belden Security Bulletin and VulnCheck Advisory.
Detection Methods for CVE-2017-20236
Indicators of Compromise
- Unusual or unexpected outbound network connections from ICX35-HWC devices
- Modified configuration files or unauthorized user accounts on the device
- Presence of unexpected processes or scripts running on the gateway
- Web server logs showing requests with shell metacharacters (;, |, $(), backticks) in input parameters
Detection Strategies
- Monitor HTTP traffic to ICX35-HWC web interfaces for requests containing command injection patterns such as shell metacharacters and command chaining syntax
- Implement network intrusion detection rules to alert on suspicious payloads targeting the device management interface
- Review web server access logs for anomalous request patterns or repeated requests to specific endpoints with varying parameter values
- Deploy network segmentation monitoring to detect unexpected communication from industrial control devices
Monitoring Recommendations
- Implement continuous monitoring of all network traffic to and from ICX35-HWC gateways
- Configure alerting for any administrative access or configuration changes on affected devices
- Establish baseline behavior profiles for cellular gateway network activity to identify deviations
- Regularly audit device configurations and compare against known-good states
How to Mitigate CVE-2017-20236
Immediate Actions Required
- Upgrade ProSoft Technology ICX35-HWC devices to firmware versions newer than 1.3 that address this vulnerability
- Restrict network access to the web management interface using firewall rules or network segmentation
- Place affected devices behind a VPN or jump host to limit exposure
- Disable the web interface if not operationally required
Patch Information
ProSoft Technology has addressed this vulnerability in firmware updates released after version 1.3. Organizations should consult the Belden Security Bulletin for specific patch information and upgrade instructions. It is strongly recommended to apply the latest available firmware to all affected devices.
Workarounds
- Implement strict network segmentation to isolate ICX35-HWC devices from untrusted networks and limit web interface accessibility
- Configure access control lists (ACLs) on network devices to restrict which IP addresses can reach the management interface
- Deploy a web application firewall (WAF) in front of the device to filter requests containing command injection patterns
- Disable remote management capabilities if not required for operations and manage devices locally when possible
# Example network segmentation configuration (Cisco IOS)
# Restrict access to ICX35-HWC management interface
access-list 100 permit tcp 10.10.10.0 0.0.0.255 host 192.168.1.100 eq 80
access-list 100 deny tcp any host 192.168.1.100 eq 80
access-list 100 permit ip any any
interface GigabitEthernet0/1
ip access-group 100 in
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
