CVE-2023-32737
📋 TL;DR
This vulnerability in SIMATIC STEP 7 Safety V18 allows attackers to execute arbitrary code by exploiting insecure .NET BinaryFormatter deserialization. Attackers can achieve remote code execution on systems running affected versions. This affects industrial control systems using this Siemens software for safety-critical programming.
💻 Affected Systems
- SIMATIC STEP 7 Safety V18
⚠️ 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 compromise allowing attacker to execute arbitrary code with application privileges, potentially leading to safety system manipulation, production disruption, or lateral movement within industrial networks.
Likely Case
Remote code execution on engineering workstations, potentially compromising safety logic programming and allowing manipulation of industrial processes.
If Mitigated
Limited impact if proper network segmentation and access controls prevent unauthorized access to engineering workstations.
🎯 Exploit Status
Requires attacker to supply malicious input to the deserialization process, typically through network access to engineering workstation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V18 Update 2
Vendor Advisory: https://cert-portal.siemens.com/productcert/html/ssa-313039.html
Restart Required: Yes
Instructions:
1. Download SIMATIC STEP 7 Safety V18 Update 2 from Siemens support portal. 2. Close all STEP 7 applications. 3. Run the update installer with administrative privileges. 4. Restart the system after installation completes.
🔧 Temporary Workarounds
Restrict network access
allLimit network access to engineering workstations using firewalls and network segmentation
Application whitelisting
windowsImplement application control to prevent unauthorized code execution
🧯 If You Can't Patch
- Implement strict network segmentation to isolate engineering workstations from untrusted networks
- Apply principle of least privilege and restrict user access to engineering workstations
🔍 How to Verify
Check if Vulnerable:
Check installed version of SIMATIC STEP 7 Safety V18 via Control Panel > Programs and FeaturesCheck Version:
wmic product where "name like 'SIMATIC STEP 7 Safety V18%'" get versionVerify Fix Applied:
Verify version shows 'V18 Update 2' or higher in installed programs list📡 Detection & Monitoring
Log Indicators:
- Unusual process creation from STEP 7 processes
- Failed deserialization attempts in application logs
- Network connections to engineering workstations from unauthorized sources
Network Indicators:
- Unusual traffic to engineering workstation ports
- Anomalous protocol usage to STEP 7 services
SIEM Query:
source="windows" AND (process_name="*step7*" OR process_name="*s7*") AND (event_id=4688 OR event_id=1) AND parent_process_name="*step7*"