CVE-2019-11244 : Exploit Details and Defense Strategies

In Kubernetes versions 1.8.x to 1.14.x, a vulnerability exists where kubectl stores schema information in a cache directory with world-writeable permissions, potentially allowing unauthorized modification of files.

Understanding CVE-2019-11244

What is CVE-2019-11244?

In Kubernetes versions 1.8.x to 1.14.x, the kubectl utility caches schema information in a directory specified by the --cache-dir parameter, which can have insecure permissions.

The Impact of CVE-2019-11244

The vulnerability could allow unauthorized users to modify cached schema files, potentially disrupting kubectl operations.

Technical Details of CVE-2019-11244

Vulnerability Description

CWE-524: Information Exposure Through Caching
Kubectl creates world-writeable cached schema files

Affected Systems and Versions

Kubernetes versions 1.8.0 to 1.14.0

Exploitation Mechanism

Attack Complexity: High
Attack Vector: Local
Privileges Required: Low
User Interaction: Required

Mitigation and Prevention

Immediate Steps to Take

Use the default --http-cache location in the $HOME directory
Point the cache directory to a location accessible only to authorized users/groups

Long-Term Security Practices

Regularly review and update file permissions
Monitor and restrict access to sensitive directories

Patching and Updates

Apply patches provided by Kubernetes to address this vulnerability