CVE-2019-6611 Explained : Impact and Mitigation
Learn about CVE-2019-6611 affecting F5's BIG-IP system versions 14.0.0-14.1.0.1, 13.0.0-13.1.1.4, 12.1.0-12.1.4, 11.6.1-11.6.3.4, and 11.5.2-11.5.8. Discover the impact, technical details, and mitigation steps.
A vulnerability in the BIG-IP system affects versions 14.0.0-14.1.0.1, 13.0.0-13.1.1.4, 12.1.0-12.1.4, 11.6.1-11.6.3.4, and 11.5.2-11.5.8, potentially leading to incorrect logic execution and system restarts.
Understanding CVE-2019-6611
This CVE identifies a vulnerability in F5's BIG-IP system that can be exploited through specific data sequences in PPTP VPN traffic.
What is CVE-2019-6611?
The vulnerability in the BIG-IP system can cause the Traffic Management Microkernel (TMM) to restart due to incorrect logic execution, impacting systems provisioned with the CGNAT module and configured with a virtual server using a PPTP profile.
The Impact of CVE-2019-6611
The vulnerability can lead to Denial of Service (DoS) conditions, disrupting the availability of affected systems.
Technical Details of CVE-2019-6611
This section provides detailed technical insights into the vulnerability.
Vulnerability Description
The vulnerability arises when processing specific rare data sequences in PPTP VPN traffic, triggering incorrect logic execution and TMM restarts.
Affected Systems and Versions
- BIG-IP versions 14.0.0-14.1.0.1, 13.0.0-13.1.1.4, 12.1.0-12.1.4, 11.6.1-11.6.3.4, and 11.5.2-11.5.8
- Systems provisioned with the CGNAT module and configured with a virtual server using a PPTP profile
Exploitation Mechanism
The vulnerability is exploited through specific data sequences in PPTP VPN traffic, causing the system to execute incorrect logic and leading to TMM restarts.
Mitigation and Prevention
Protecting systems from CVE-2019-6611 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Apply vendor-supplied patches promptly
- Monitor system logs for unusual restarts or core file generation
- Restrict network access to critical systems
Long-Term Security Practices
- Regularly update and patch systems to address vulnerabilities
- Implement network segmentation to contain potential attacks
- Conduct regular security assessments and audits
Patching and Updates
- F5 has released patches to address the vulnerability
- Regularly check for updates and apply them to ensure system security