Introduction
VxWorks is a popular real-time operating system that powers embedded devices across many critical infrastructure sectors like aerospace, medical, industrial, and automotive. As such, VxWorks vulnerabilities present serious cybersecurity risks that must be proactively assessed and remediated. In this article, I will provide an in-depth look at the most critical VxWorks vulnerabilities, outline key strategies for risk assessment, and detail effective methods for remediation and mitigation.
Background on VxWorks and Associated Vulnerabilities
VxWorks is a real-time operating system developed by Wind River Systems. It has been widely adopted in embedded devices and industrial control systems across critical infrastructure. However, VxWorks has a large attack surface and lacks modern mitigations, making it an attractive target for attackers.
Some of the most dangerous VxWorks vulnerabilities include:
Urgent/11 Vulnerabilities
- Discovered in 2019, the set of Urgent/11 vulnerabilities affect the IPnet TCP/IP stack in VxWorks.
- They allow remote code execution and total system compromise.
- Urgent/11 has a CVSS score of 9.8 out of 10, making it critical severity.
Ripple20 Vulnerabilities
- Uncovered in 2020, Ripple20 consists of 19 vulnerabilities stemming from Treck IP network stack code used in VxWorks.
- These flaws allow remote code execution, denial of service, and information leaks.
- Ripple20 has a CVSS score range of 7.5-8.2, marking it high severity.
Assessing VxWorks Vulnerability Risks
To reduce the chance of successful exploitation, organizations must systematically assess VxWorks vulnerability risks across their environment. Here are some key strategies:
Inventory Networked Devices Running VxWorks
- Perform network scans using tools like Nmap to identify all active VxWorks devices. Maintain an inventory.
Identify VxWorks Version and Build Details
- Fingerprint the exact VxWorks version and build details on each device via banners and targeted scanning.
Check for Vulnerable Components
- Scan for exposed services relying on vulnerable components like IPnet or Treck stacks.
Consult Public Vulnerability Databases
- Cross reference known CVEs and vulnerability data from sources like CISA, MITRE, and NVD.
Prioritize Devices for Remediation
- Use risk matrices and frameworks like CVSS scoring to prioritize vulnerabilities for patching and remediation. Focus on internet-facing and mission critical devices first.
Confirm Vulnerability Exploits in the Wild
- Monitor threat feeds and stay aware of exploitation attempts, tools, and malware targeting VxWorks in the wild.
Remediating and Mitigating VxWorks Vulnerabilities
Once vulnerable VxWorks devices are identified and prioritized, concrete steps can be taken to eliminate or mitigate risks. Here are key remediation and mitigation strategies:
Patch and Update VxWorks Versions
- Deploy available patches from Wind River Systems to update VxWorks versions and remediate known vulnerabilities.
Update Vulnerable Components and Libraries
- Where possible, update or replace risky components like IPnet and Treck stacks with patched software.
Apply Compensating Controls
- Where patching is not viable, use firewall rules, VLAN segmentation, and other controls to isolate and limit access to vulnerable devices.
Employ Custom Mitigations
- For zero-day or unpatchable flaws, create custom application firewall rules, integrity checks, and other mitigations tuned to specific exploits.
Reset Device Credentials
- Change default credentials on all VxWorks devices. Disable telnet and insecure remote access protocols.
Monitor VxWorks Devices for Threat Activity
- Deploy enhanced monitoring, endpoint detection, and analytics to quickly detect active exploitation of VxWorks vulnerabilities.
Conclusion
VxWorks powers mission critical systems, but has significant cybersecurity risks that must be managed. By taking a proactive approach to vulnerability assessment and remediation using the strategies outlined above, organizations can reduce their exposure to threats targeting VxWorks. However, defending VxWorks requires continuous vigilance and ongoing vulnerability management due to its large attack surface and risky legacy components.
