CVE-2025-3947
📋 TL;DR
This CVE describes an integer underflow vulnerability in Honeywell Experion PKS Control Data Access (CDA) component. Attackers can manipulate input data to cause improper integer checking during subtraction, potentially leading to denial of service. Affected systems include Honeywell Experion PKS versions 520.1 through 520.2 TCU9 and 530 through 530 TCU3 running on C300, FIM, UOC, CN100, HCA, C300PM, and C200E products.
💻 Affected Systems
- C300 PCNT02
- C300 PCNT05
- FIM4
- FIM8
- UOC
- CN100
- HCA
- C300PM
- C200E
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete system crash or unavailability of the Experion PKS control system, potentially disrupting industrial processes and safety systems.
Likely Case
Service disruption affecting specific control functions or data access capabilities, requiring system restart.
If Mitigated
Limited impact to non-critical functions with proper network segmentation and monitoring in place.
🎯 Exploit Status
Integer underflow vulnerabilities typically require specific input manipulation. No public exploit code is mentioned in the CVE description.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 520.2 TCU9 HF1 and 530.1 TCU3 HF1
Vendor Advisory: https://process.honeywell.com/
Restart Required: Yes
Instructions:
1. Download the appropriate hotfix from Honeywell's support portal. 2. Apply hotfix to affected Experion PKS systems. 3. Restart systems as required. 4. Verify successful update.
🔧 Temporary Workarounds
Network Segmentation
allIsolate Experion PKS systems from untrusted networks and implement strict firewall rules.
Access Control Restrictions
allLimit access to CDA component to only authorized personnel and systems.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate affected systems from potential attackers
- Deploy intrusion detection systems and monitor for unusual traffic patterns to CDA components
🔍 How to Verify
Check if Vulnerable:
Check Experion PKS version against affected ranges: 520.1-520.2 TCU9 or 530-530 TCU3Check Version:
Check via Experion PKS system administration interface or consult Honeywell documentationVerify Fix Applied:
Verify system version shows 520.2 TCU9 HF1 or 530.1 TCU3 HF1 after patching📡 Detection & Monitoring
Log Indicators:
- Unusual CDA component errors
- System crash logs
- Unexpected process terminations
Network Indicators:
- Unusual traffic patterns to CDA ports
- Multiple failed connection attempts
SIEM Query:
Search for: (source_ip contains industrial_network) AND (event_type contains 'crash' OR 'denial') AND (component contains 'CDA' OR 'Control Data Access')