CVE-2020-5933 : Security Advisory and Response

A vulnerability in F5 BIG-IP versions 11.6.1-15.1.0.5 could allow a DoS attack, triggering an out-of-memory condition.

Understanding CVE-2020-5933

What is CVE-2020-5933?

The vulnerability affects BIG-IP systems with specific versions, enabling a Slowloris-style attack to exhaust system memory.

The Impact of CVE-2020-5933

The vulnerability could lead to a denial-of-service (DoS) condition, potentially disrupting system availability and performance.

Technical Details of CVE-2020-5933

Vulnerability Description

When a BIG-IP system with an HTTP compression profile processes compressed HTTP messages needing deflation, it can result in an out-of-memory state due to a Slowloris-style attack.

Affected Systems and Versions

BIG-IP versions 15.1.0-15.1.0.5
BIG-IP versions 14.1.0-14.1.2.3
BIG-IP versions 13.1.0-13.1.3.4
BIG-IP versions 12.1.0-12.1.5.1
BIG-IP versions 11.6.1-11.6.5.1

Exploitation Mechanism

The vulnerability can be exploited by sending compressed HTTP message payloads that require deflation to a virtual server configured with an HTTP compression profile, causing an out-of-memory condition.

Mitigation and Prevention

Immediate Steps to Take

Apply the necessary patches provided by F5 Networks.
Implement network-level protections to mitigate DoS attacks.

Long-Term Security Practices

Regularly update and patch BIG-IP systems to address known vulnerabilities.
Monitor system resources and behavior for unusual activity that may indicate a DoS attack.
Follow security best practices to enhance system resilience.

Patching and Updates

Ensure timely installation of security patches and updates from F5 Networks to mitigate the CVE-2020-5933 vulnerability.