CVE-2020-5423 : Security Advisory and Response

CAPI (Cloud Controller) versions prior to 1.101.0 are vulnerable to a denial-of-service attack where an unauthenticated attacker can exploit YAML parsing, leading to excessive CPU and RAM consumption.

Understanding CVE-2020-5423

Cloud Controller vulnerability impacting Cloud Foundry products.

What is CVE-2020-5423?

Denial-of-service vulnerability in CAPI (Cloud Controller) versions < 1.101.0
Attackers can send malicious YAML files to specific endpoints, causing resource exhaustion.

The Impact of CVE-2020-5423

CVSS Base Score: 7.5 (High)
Attack Vector: Network
Availability Impact: High
Attack Complexity: Low
CWE-400: Uncontrolled Resource Consumption

Technical Details of CVE-2020-5423

Vulnerability specifics and affected systems.

Vulnerability Description

Unauthenticated attackers can trigger resource exhaustion via specially-crafted YAML files.

Affected Systems and Versions

Products: CAPI, CF Deployment
Versions:
CAPI: < 1.101.0
CF Deployment: < 15.0.0

Exploitation Mechanism

Attackers exploit YAML parsing in CAPI to overwhelm CPU and RAM.

Mitigation and Prevention

Steps to mitigate and prevent exploitation.

Immediate Steps to Take

Update CAPI and CF Deployment to non-vulnerable versions.
Implement network controls to limit access to affected endpoints.

Long-Term Security Practices

Regularly monitor and audit YAML parsing functionality.
Educate users on safe YAML file handling practices.

Patching and Updates

Apply patches provided by Cloud Foundry to address the vulnerability.