CVE-2019-11249 : Exploit Details and Defense Strategies

Kubernetes has a vulnerability in the kubectl cp command that allows symlink directory traversal, potentially leading to arbitrary code execution.

Understanding CVE-2019-11249

This CVE affects Kubernetes versions prior to 1.13.9, 1.14.5, and 1.15.2, as well as versions 1.1 to 1.12.

What is CVE-2019-11249?

The kubectl cp command in Kubernetes facilitates file transfer between containers and the user's local machine. However, if the tar binary within the container is compromised, it can execute arbitrary code, posing a security risk.

The Impact of CVE-2019-11249

The vulnerability allows an attacker to write files to any directory on the user's machine when the kubectl cp command is executed, potentially leading to unauthorized access and malicious activities.

Technical Details of CVE-2019-11249

The following technical details provide insight into the vulnerability and its implications:

Vulnerability Description

The kubectl cp vulnerability arises from the use of the tar utility within containers, enabling attackers to exploit symlink directory traversal for malicious file writing.

Affected Systems and Versions

Kubernetes versions prior to 1.13.9, 1.14.5, and 1.15.2
Kubernetes versions 1.1 to 1.12

Exploitation Mechanism

Attack Complexity: High
Attack Vector: Network
Privileges Required: Low
User Interaction: Required
Integrity Impact: High

Mitigation and Prevention

To address CVE-2019-11249 and enhance system security, consider the following mitigation strategies:

Immediate Steps to Take

Update Kubernetes to versions 1.13.9, 1.14.5, or 1.15.2 to eliminate the vulnerability.
Avoid using the kubectl cp command in untrusted environments.

Long-Term Security Practices

Regularly monitor and update Kubernetes for security patches.
Implement least privilege access controls to limit potential damage from security breaches.

Patching and Updates

Apply security patches promptly to ensure the latest fixes and enhancements are in place.