Executive Summary
A signal handler race condition in OpenSSH server (sshd) allows remote code execution.
This high vulnerability with CVSS score 8.1 requires prompt attention from Australian organizations using OpenSSH OpenSSH.
Technical Details
Vulnerability Overview
- CVE ID: CVE-2024-6387
- CVSS Score: 8.1 (High)
- Published: July 01, 2024
- Vendor: OpenSSH
- Product: OpenSSH
- Category: Race Condition
Impact Assessment
Unauthenticated remote attackers can execute arbitrary code as root.
Affected Systems
Organizations using OpenSSH OpenSSH should immediately assess their exposure to this vulnerability.
- Check version numbers against affected ranges
- Review security advisories from OpenSSH
- Assess internet-facing exposure
- Conduct vulnerability scans
Threat Level
Based on CVSS 8.1 score and vulnerability type (Race Condition), this represents a high threat to Australian organizations.
Priority: 🟠HIGH
Mitigation and Remediation
Immediate Actions
Update to OpenSSH 9.8p1 or later, or apply vendor patches
General Remediation Steps
- Identify all instances of OpenSSH OpenSSH in your environment
- Review vendor security advisories for specific patch information
- Test patches in non-production environment if possible
- Deploy patches to production systems following change management procedures
- Verify patch deployment and conduct post-patch validation
- Monitor systems for signs of exploitation or compromise
Compensating Controls (If Immediate Patching Not Possible)
- Implement network segmentation to limit exposure
- Deploy additional monitoring and detection capabilities
- Restrict access to affected systems using ACLs or firewall rules
- Enable additional logging and alerting
- Conduct more frequent security assessments
- Document exceptions and remediation timeline
Australian Organizational Guidance
Compliance Considerations
- Essential Eight: Patch applications within timeframes appropriate to risk (Critical: 48 hours)
- ISM Controls: Follow ACSC guidelines for vulnerability management
- Privacy Act: Consider notification requirements if data exposure possible
- Industry Standards: Align with sector-specific security requirements
- SOCI Act: Critical infrastructure entities must report security incidents
Resources for Australian Organizations
Detection and Monitoring
Indicators to Monitor
- Unusual authentication patterns or failures
- Unexpected system configuration changes
- Anomalous network traffic patterns
- Suspicious process execution
- Unauthorized access attempts
- Unusual outbound connections
Log Analysis
Review system logs for indicators of exploitation. Focus on:
- Authentication logs for unusual login patterns
- System logs for configuration changes
- Application-specific logs for OpenSSH
- Network traffic logs for C2 communications
- Security tool alerts and correlations
SIEM Detection Rules
Implement detection rules specific to Race Condition attacks. Monitor for patterns consistent with this vulnerability and establish baselines for normal behavior.
References and Resources
Frequently Asked Questions
How serious is CVE-2024-6387?
With a CVSS score of 8.1, this is classified as high. Organizations should prioritize remediation based on their risk assessment and compliance requirements.
How do I know if I'm affected?
Check if you're using OpenSSH OpenSSH. Review the vendor's security advisory for specific affected version ranges and configurations. Conduct vulnerability scans and asset inventory checks.
What should Australian organizations do?
Follow ACSC guidance for vulnerability management. Assess your exposure, prioritize based on risk, and implement patches or compensating controls as appropriate. Document all actions taken and ensure senior management is informed.
Where can I get patches?
Obtain patches directly from OpenSSH through their official support channels or customer portal. Ensure patches are validated before deployment and test in non-production environments first.
What if I can't patch immediately?
Implement compensating controls as listed above. Document the exception, establish a remediation timeline, and increase monitoring. Report to senior management and consider third-party security services for additional support.
Need Expert Assistance?
Australian cybersecurity professionals can help assess your exposure to CVE-2024-6387 and implement appropriate remediation strategies.