CVE-2021-42024
📋 TL;DR
CVE-2021-42024 is an out-of-bounds write vulnerability in Simcenter STAR-CCM+ Viewer that allows remote code execution when parsing malicious scene files. All users of STAR-CCM+ Viewer versions before 2021.3.1 are affected. An attacker could execute arbitrary code with the privileges of the user running the viewer.
💻 Affected Systems
- Simcenter STAR-CCM+ Viewer
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through remote code execution, allowing attacker to install malware, exfiltrate data, or pivot to other systems.
Likely Case
Attacker gains control of the workstation running STAR-CCM+ Viewer, potentially accessing engineering data and using the system as a foothold for lateral movement.
If Mitigated
Limited impact through network segmentation and least privilege, with potential for denial of service or limited data exposure.
🎯 Exploit Status
Exploitation requires user interaction to open a malicious scene file, but no authentication is needed. The vulnerability is in file parsing logic.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2021.3.1 or later
Vendor Advisory: https://cert-portal.siemens.com/productcert/pdf/ssa-161331.pdf
Restart Required: Yes
Instructions:
1. Download STAR-CCM+ Viewer 2021.3.1 or later from Siemens support portal. 2. Uninstall previous version. 3. Install updated version. 4. Restart system.
🔧 Temporary Workarounds
Restrict scene file execution
windowsBlock execution of starview+.exe from untrusted locations or restrict file associations
Use Windows Group Policy or AppLocker to restrict starview+.exe execution
User awareness training
allTrain users to only open scene files from trusted sources
🧯 If You Can't Patch
- Network segmentation: Isolate systems running STAR-CCM+ Viewer from critical networks
- Least privilege: Run STAR-CCM+ Viewer with minimal user privileges, not as administrator
🔍 How to Verify
Check if Vulnerable:
Check STAR-CCM+ Viewer version in Help > About. If version is below 2021.3.1, system is vulnerable.Check Version:
On Windows: Check Help > About in STAR-CCM+ Viewer GUI. On Linux: Check installation directory or package manager.Verify Fix Applied:
Verify version is 2021.3.1 or higher in Help > About menu.📡 Detection & Monitoring
Log Indicators:
- Application crashes of starview+.exe
- Unexpected process creation from STAR-CCM+ Viewer
- Failed scene file parsing attempts
Network Indicators:
- Unexpected outbound connections from systems running STAR-CCM+ Viewer
- Scene file downloads from untrusted sources
SIEM Query:
Process:starview+.exe AND (EventID:1000 OR EventID:1001) OR FileExtension:.scn AND SourceIP:External