CVE-2020-5420 : What You Need to Know

Cloud Foundry Routing (Gorouter) versions prior to 0.206.0 allow a malicious developer to cause denial-of-service by pushing an app with specially crafted HTTP responses.

Understanding CVE-2020-5420

Cloud Foundry Gorouter vulnerability impacting versions prior to 0.206.0.

What is CVE-2020-5420?

This CVE identifies a vulnerability in Cloud Foundry Routing (Gorouter) that allows a malicious developer to execute a denial-of-service attack on the CF cluster by pushing an application that generates specific HTTP responses leading to Gorouter crashes.

The Impact of CVE-2020-5420

CVSS Base Score: 7.7 (High)
Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
Availability Impact: High
Scope: Changed
CWE-754: Improper Check for Unusual or Exceptional Conditions

Technical Details of CVE-2020-5420

Cloud Foundry Gorouter vulnerability details.

Vulnerability Description

The vulnerability allows a malicious developer to exploit Gorouter versions prior to 0.206.0, causing denial-of-service by manipulating HTTP responses.

Affected Systems and Versions

Products: Routing, CF Deployment
Vendor: Cloud Foundry
Affected Versions:
Routing: < 0.206.0
CF Deployment: < 13.15.0

Exploitation Mechanism

The attacker with 'cf push' access can push an application returning crafted HTTP responses to trigger Gorouter crashes.

Mitigation and Prevention

Steps to mitigate and prevent the CVE-2020-5420 vulnerability.

Immediate Steps to Take

Update affected systems to versions 0.206.0 for Routing and 13.15.0 for CF Deployment.
Monitor and restrict 'cf push' access to prevent malicious app deployments.

Long-Term Security Practices

Regularly review and update access controls and permissions within Cloud Foundry environments.
Conduct security training for developers to recognize and prevent similar vulnerabilities.

Patching and Updates

Apply patches provided by Cloud Foundry promptly to address the vulnerability.