CVE-2019-11246 Explained : Impact and Mitigation

A vulnerability in Kubernetes allows malicious containers to write files to any location on the user's machine when using the kubectl cp command.

Understanding CVE-2019-11246

This CVE affects Kubernetes versions prior to 1.12.9, 1.13.6, and 1.14.2, as well as versions 1.1 to 1.11.

What is CVE-2019-11246?

The kubectl cp command in Kubernetes facilitates file transfer between containers and the user's machine. However, if a malicious container contains a tampered tar binary, it can execute arbitrary code on the user's machine, potentially leading to harmful outcomes.

The Impact of CVE-2019-11246

The vulnerability has a CVSS base score of 6.4, indicating a medium severity issue. It has a high impact on confidentiality, integrity, and availability, requiring high privileges and user interaction for exploitation.

Technical Details of CVE-2019-11246

The following technical details provide insight into the vulnerability:

Vulnerability Description

When using kubectl cp, a malicious tar binary within a container can write files to any path on the user's machine, limited only by the local user's system permissions.

Affected Systems and Versions

Kubernetes versions prior to 1.12.9, 1.13.6, and 1.14.2
Kubernetes versions 1.1 to 1.11

Exploitation Mechanism

The vulnerability is exploited by running a malicious tar binary within a container, allowing an attacker to write files to any location on the user's machine during the file transfer process.

Mitigation and Prevention

Taking immediate steps and implementing long-term security practices are crucial to mitigating the risks associated with CVE-2019-11246.

Immediate Steps to Take

Update Kubernetes to a patched version that addresses the vulnerability.
Avoid using the kubectl cp command until the system is patched.

Long-Term Security Practices

Regularly update Kubernetes and other software components to prevent vulnerabilities.
Implement container security best practices to minimize the impact of potential exploits.

Patching and Updates

Apply the latest patches provided by Kubernetes to fix the vulnerability and enhance system security.