CVE-2021-40085 : What You Need to Know

OpenStack Neutron before 16.4.1, 17.x before 17.2.1, and 18.x before 18.1.1 allows authenticated attackers to reconfigure dnsmasq via a crafted extra_dhcp_opts value.

Understanding CVE-2021-40085

This CVE relates to a security issue in OpenStack Neutron that could be exploited by authenticated attackers to manipulate dnsmasq using specially crafted extra_dhcp_opts values.

What is CVE-2021-40085?

The vulnerability allows authenticated attackers to modify the configuration of dnsmasq in OpenStack Neutron by providing a malicious extra_dhcp_opts parameter.

The Impact of CVE-2021-40085

The exploitation of this vulnerability could result in unauthorized reconfiguration of dnsmasq in OpenStack Neutron, leading to potential security breaches and disruptions in network operations.

Technical Details of CVE-2021-40085

CVE-2021-40085 has the following technical details:

Vulnerability Description

The issue in OpenStack Neutron before versions 16.4.1, 17.2.1, and 18.1.1 allows for unauthorized manipulation of dnsmasq configurations.

Affected Systems and Versions

Product: OpenStack Neutron
Versions: 16.4.1 and prior, 17.2.1 and prior, 18.1.1 and prior

Exploitation Mechanism

Attackers with authenticated access can exploit the vulnerability by providing a crafted extra_dhcp_opts value to reconfigure dnsmasq in the affected OpenStack versions.

Mitigation and Prevention

To address CVE-2021-40085, consider the following steps:

Immediate Steps to Take

Apply the vendor-supplied patches immediately.
Monitor network activity for any unauthorized changes.

Long-Term Security Practices

Conduct regular security assessments and audits.
Implement the principle of least privilege to limit access.

Patching and Updates

Update OpenStack Neutron to versions 16.4.1, 17.2.1, or 18.1.1 to mitigate the vulnerability effectively.