CVE-2022-37394 : Exploit Details and Defense Strategies

An issue was discovered in OpenStack Nova before versions 23.2.2, 24.1.2, and 25.0.2. This vulnerability allows an authenticated user to trigger a denial of service by creating specific network configurations. Read on to understand the impact, technical details, and mitigation strategies related to CVE-2022-37394.

Understanding CVE-2022-37394

OpenStack Nova versions before 23.2.2, 24.x before 24.1.2, and 25.x before 25.0.2 are affected by a vulnerability that can lead to a denial of service attack. The exploitation of this issue involves a specific sequence of actions by an authenticated user within an OpenStack environment.

What is CVE-2022-37394?

CVE-2022-37394 is a security flaw in OpenStack Nova that allows an authenticated user to disrupt the compute service's functionality, potentially resulting in a denial of service. This vulnerability arises from changing the virtual network interface controller type, triggering a failure in service restart.

The Impact of CVE-2022-37394

The impact of CVE-2022-37394 is the potential disruption of the compute service in OpenStack Nova deployments. By exploiting this vulnerability, an attacker could cause the compute service to fail to restart, leading to a denial of service condition.

Technical Details of CVE-2022-37394

Vulnerability Description

The vulnerability in CVE-2022-37394 arises when an authenticated user creates specific network configurations involving neutron ports and vNIC types within OpenStack Nova. By changing the vNIC type after creating an instance, the compute service may fail to restart, causing a denial of service.

Affected Systems and Versions

OpenStack Nova versions before 23.2.2, 24.x before 24.1.2, and 25.x before 25.0.2 are affected by CVE-2022-37394. Specifically, only Nova deployments configured with SR-IOV are vulnerable to this issue.

Exploitation Mechanism

To exploit CVE-2022-37394, an authenticated user needs to create a neutron port with a direct vNIC type, bind an instance to that port, and then change the vNIC type of the bound port to macvtap. This sequence of actions can trigger a failure in the compute service, potentially leading to a denial of service.

Mitigation and Prevention

Immediate Steps to Take

Users are advised to update their OpenStack Nova installations to versions 23.2.2, 24.1.2, or 25.0.2 to mitigate the vulnerability. Additionally, administrators should review their network configurations and ensure proper vNIC type handling to prevent exploitation.

Long-Term Security Practices

To enhance the security of OpenStack deployments, organizations should regularly monitor for security updates and apply patches promptly. Training personnel on secure network configuration practices can also help prevent similar vulnerabilities.

Patching and Updates

OpenStack Nova users should stay informed about security advisories from the project maintainers. Applying security patches and updates in a timely manner is crucial to safeguarding the infrastructure against known vulnerabilities.