CVE-2019-9946 Explained : Impact and Mitigation
Learn about CVE-2019-9946 affecting Kubernetes due to a network firewall misconfiguration in CNCF CNI 0.7.4. Find out the impact, affected versions, and mitigation steps.
Kubernetes is affected by a network firewall misconfiguration in the Cloud Native Computing Foundation (CNCF) CNI (Container Networking Interface) 0.7.4. The misconfiguration occurs in the CNI 'portmap' plugin, which is responsible for setting up HostPorts for CNI. This issue has been addressed in CNI 0.7.5 and Kubernetes 1.11.9, 1.12.7, 1.13.5, and 1.14.0.
Understanding CVE-2019-9946
This CVE involves a vulnerability in Kubernetes due to a network firewall misconfiguration in the CNCF CNI 0.7.4.
What is CVE-2019-9946?
The misconfiguration in the CNI 'portmap' plugin allows HostPort rules to take precedence over more specific service definition rules, potentially leading to a security issue.
The Impact of CVE-2019-9946
The vulnerability could allow incoming traffic to match HostPort/portmap rules, even if there are more specific service definition rules like NodePorts later in the chain.
Technical Details of CVE-2019-9946
This section provides detailed technical information about the CVE.
Vulnerability Description
The CNI 'portmap' plugin misconfiguration in Kubernetes allows HostPort rules to override more specific service definition rules, potentially leading to security risks.
Affected Systems and Versions
- Affected version: CNCF CNI 0.7.4
- Resolved versions: CNI 0.7.5, Kubernetes 1.11.9, 1.12.7, 1.13.5, and 1.14.0
Exploitation Mechanism
The misconfiguration in the 'portmap' plugin gives precedence to HostPort rules over more specific service definition rules, potentially allowing unauthorized traffic.
Mitigation and Prevention
Protect your systems from CVE-2019-9946 with the following steps:
Immediate Steps to Take
- Update to the fixed versions: CNI 0.7.5, Kubernetes 1.11.9, 1.12.7, 1.13.5, or 1.14.0
- Review and adjust firewall configurations to mitigate the risk of misconfigurations.
Long-Term Security Practices
- Regularly monitor and update Kubernetes and related components to ensure security patches are applied promptly.
- Conduct security audits to identify and address any misconfigurations that could lead to vulnerabilities.
Patching and Updates
Ensure timely patching and updates for Kubernetes and associated components to prevent exploitation of known vulnerabilities.