CVE-2019-6677 : Vulnerability Insights and Analysis

A vulnerability in F5 BIG-IP versions 12.1.0-15.0.1 can lead to a denial of service (DoS) condition under specific circumstances.

Understanding CVE-2019-6677

This CVE involves a potential DoS risk on F5 BIG-IP devices due to a specific configuration scenario.

What is CVE-2019-6677?

CVE-2019-6677 is a vulnerability that can cause Traffic Management Microkernel (TMM) to halt processing traffic on F5 BIG-IP devices when certain conditions are met.

The Impact of CVE-2019-6677

The vulnerability can result in a denial of service (DoS) condition, impacting the availability of services and potentially causing disruption to network traffic.

Technical Details of CVE-2019-6677

This section delves into the technical aspects of the CVE.

Vulnerability Description

The issue arises when utilizing a TCP profile with custom TCP congestion control settings alongside an iRule on BIG-IP versions 12.1.0-15.0.1, causing TMM to cease processing traffic.

Affected Systems and Versions

F5 BIG-IP versions 15.0.0-15.0.1
F5 BIG-IP versions 14.1.0-14.1.2
F5 BIG-IP versions 14.0.0-14.0.1
F5 BIG-IP versions 13.1.0-13.1.3.1
F5 BIG-IP versions 12.1.0-12.1.5

Exploitation Mechanism

The vulnerability is triggered by the use of a TCP profile with custom congestion control settings in conjunction with an iRule, leading to TMM halting traffic processing.

Mitigation and Prevention

Protecting systems from CVE-2019-6677 is crucial to prevent potential service disruptions.

Immediate Steps to Take

Apply vendor-supplied patches or updates promptly.
Review and adjust TCP profile and iRule configurations to mitigate the risk.

Long-Term Security Practices

Regularly monitor vendor security advisories for updates.
Implement network segmentation and access controls to limit exposure to potential attacks.

Patching and Updates

Ensure timely installation of patches and updates provided by F5 to address the vulnerability.