CVE-2019-6619 : Exploit Details and Defense Strategies

A vulnerability in F5's BIG-IP Traffic Management Microkernel (TMM) could lead to a denial of service (DoS) condition.

Understanding CVE-2019-6619

This CVE affects F5's BIG-IP products, potentially causing TMM restarts under specific conditions.

What is CVE-2019-6619?

The issue arises in BIG-IP versions 14.0.0-14.1.0.1, 13.0.0-13.1.1.4, and 12.1.0-12.1.4 due to a restart scenario triggered by certain HTTP/2 and ALPN configurations.

The Impact of CVE-2019-6619

The vulnerability could result in a DoS situation, disrupting services and potentially causing downtime for affected systems.

Technical Details of CVE-2019-6619

This section delves into the specifics of the vulnerability.

Vulnerability Description

The TMM on specified BIG-IP versions may restart when processing traffic with specific ALPN extension configurations, leading to service interruptions.

Affected Systems and Versions

Products: BIG-IP (LTM, AAM, AFM, APM, ASM, Link Controller, PEM, WebAccelerator)
Versions: 14.0.0-14.1.0.1, 13.0.0-13.1.1.4, 12.1.0-12.1.4

Exploitation Mechanism

The restart occurs when a virtual server utilizes an HTTP/2 profile with ALPN enabled and processes traffic with a zero ALPN extension size.

Mitigation and Prevention

Protecting systems from this vulnerability is crucial.

Immediate Steps to Take

Apply vendor-supplied patches promptly
Monitor system logs for unusual TMM restarts
Implement network-level protections to mitigate DoS risks

Long-Term Security Practices

Regularly update and patch F5 products
Conduct security assessments to identify and address vulnerabilities
Follow best practices for configuring and securing BIG-IP deployments

Patching and Updates

Ensure timely installation of patches provided by F5 to address the CVE-2019-6619 vulnerability.