CVE-2020-35198
📋 TL;DR
CVE-2020-35198 is a critical integer overflow vulnerability in Wind River VxWorks 7's memory allocator that allows attackers to cause memory corruption. This affects systems running VxWorks 7, potentially leading to remote code execution or denial of service. Organizations using VxWorks 7 in embedded systems, IoT devices, or industrial control systems are at risk.
💻 Affected Systems
- Wind River VxWorks 7
📦 What is this software?
Vxworks by Windriver
Vxworks by Windriver
Vxworks by Windriver
Vxworks by Windriver
Vxworks by Windriver
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, allowing attackers to execute arbitrary code with highest privileges.
Likely Case
Denial of service through system crashes or instability, potentially disrupting critical operations in embedded systems.
If Mitigated
Limited impact with proper network segmentation and exploit mitigations, though memory corruption could still cause instability.
🎯 Exploit Status
While no public PoC exists, the high CVSS score and integer overflow nature suggest reliable exploitation is feasible. Attackers would need to trigger specific memory allocation patterns.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: VxWorks 7 SR0620 and later
Vendor Advisory: https://support2.windriver.com/index.php?page=cve&on=view&id=CVE-2020-35198
Restart Required: Yes
Instructions:
1. Download VxWorks 7 SR0620 or later from Wind River support portal. 2. Apply the update following Wind River's patch deployment procedures. 3. Rebuild and redeploy affected VxWorks images. 4. Restart all affected systems.
🔧 Temporary Workarounds
Memory allocation monitoring
allImplement runtime monitoring for abnormal calloc() usage patterns
Network isolation
allIsolate VxWorks systems from untrusted networks using firewalls and segmentation
🧯 If You Can't Patch
- Implement strict network segmentation to isolate vulnerable systems
- Deploy intrusion detection systems to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check VxWorks version: In VxWorks shell, run 'version' command and verify if version is prior to SR0620.Check Version:
versionVerify Fix Applied:
After patching, verify version is SR0620 or later using 'version' command and test memory allocation functions.📡 Detection & Monitoring
Log Indicators:
- System crashes or reboots
- Memory allocation errors in system logs
- Abnormal process termination
Network Indicators:
- Unexpected network traffic to VxWorks systems
- Connection attempts to unusual ports
SIEM Query:
source="vxworks" AND (event_type="crash" OR event_type="memory_error" OR message="*calloc*")🔗 References
- https://support2.windriver.com/index.php?page=cve&on=view&id=CVE-2020-35198
- https://support2.windriver.com/index.php?page=security-notices
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://support2.windriver.com/index.php?page=cve&on=view&id=CVE-2020-35198
- https://support2.windriver.com/index.php?page=security-notices
- https://www.oracle.com/security-alerts/cpuapr2022.html
