CVE-2017-16239 : Exploit Details and Defense Strategies

OpenStack Nova versions 14.0.9, 15.x through 15.0.7, and 16.x through 16.0.2 are vulnerable to an issue that allows authenticated users to bypass filters by rebuilding an instance.

Understanding CVE-2017-16239

This CVE involves a vulnerability in OpenStack Nova that affects instances using the Nova Filter Scheduler.

What is CVE-2017-16239?

In OpenStack Nova versions 14.0.9, 15.x through 15.0.7, and 16.x through 16.0.2, an authenticated user can circumvent the Filter Scheduler by rebuilding an instance, bypassing imposed filters like ImagePropertiesFilter or IsolatedHostsFilter.

The Impact of CVE-2017-16239

All setups utilizing Nova Filter Scheduler are impacted by this vulnerability, potentially leading to unauthorized access and security breaches.

Technical Details of CVE-2017-16239

OpenStack Nova vulnerability details and affected systems.

Vulnerability Description

The vulnerability allows authenticated users to bypass filters by rebuilding instances, posing a risk of unauthorized access.

Affected Systems and Versions

OpenStack Nova versions 14.0.9, 15.x through 15.0.7, and 16.x through 16.0.2

Exploitation Mechanism

Authenticated users can exploit the vulnerability by rebuilding instances to bypass imposed filters.

Mitigation and Prevention

Steps to mitigate and prevent the CVE-2017-16239 vulnerability.

Immediate Steps to Take

Update to version 14.x after 14.0.10, 15.x after 15.0.8, or 16.x after 16.0.3 as recommended.

Long-Term Security Practices

Regularly monitor and update OpenStack Nova to ensure the latest security patches are applied.
Implement strong authentication mechanisms and access controls.

Patching and Updates

Stay informed about security advisories and promptly apply patches to address known vulnerabilities.