CVE-2017-5142
📋 TL;DR
This vulnerability in Honeywell XL Web II controllers allows low-privileged users to access privileged functions by visiting a specific URL, enabling unauthorized parameter changes. It affects Honeywell XL1000C500 and XLWeb 500 controllers with specific firmware versions. This is an improper privilege management issue that could allow attackers to manipulate industrial control system parameters.
💻 Affected Systems
- Honeywell XL1000C500 XL Web II controller
- Honeywell XLWeb 500 controller
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
An attacker could modify critical industrial control parameters, potentially causing physical damage, safety hazards, or operational disruption in industrial environments.
Likely Case
Unauthorized users could change system configurations, disrupt operations, or gain elevated privileges within the control system.
If Mitigated
With proper network segmentation and access controls, impact would be limited to isolated network segments with minimal operational disruption.
🎯 Exploit Status
Exploitation requires low-privileged access and knowledge of specific URL. No public exploit code identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: XL1000C500: XLWebExe-2-02-00 or later; XLWeb 500: XLWebExe-1-02-09 or later
Vendor Advisory: https://ics-cert.us-cert.gov/advisories/ICSA-17-033-01
Restart Required: Yes
Instructions:
1. Download updated firmware from Honeywell support portal. 2. Backup current configuration. 3. Apply firmware update following vendor instructions. 4. Restart controller. 5. Verify proper operation.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected controllers from general network access and restrict to necessary connections only.
Access Control Restrictions
allImplement strict access controls and limit user privileges to minimum necessary for operations.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate affected controllers
- Apply principle of least privilege and audit all user accounts
🔍 How to Verify
Check if Vulnerable:
Check firmware version via controller web interface or management console. Compare against affected versions.Check Version:
Check via controller web interface or vendor-specific management toolsVerify Fix Applied:
Verify firmware version is updated to patched versions and test that low-privileged users cannot access privileged functions.📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to privileged URLs
- Unexpected parameter changes by low-privileged users
Network Indicators:
- HTTP requests to specific controller URLs from unauthorized users
SIEM Query:
source="controller_logs" AND (url_path="*privileged*" OR user_privilege="low") AND action="modify"