CVE-2020-2031 Explained : Impact and Mitigation

An integer underflow vulnerability in the dnsproxyd component of the PAN-OS management interface allows authenticated administrators to issue a command that causes denial of service to all PAN-OS services.

Understanding CVE-2020-2031

This CVE involves an integer underflow vulnerability in PAN-OS, impacting certain versions and allowing for denial of service attacks.

What is CVE-2020-2031?

The vulnerability in the dnsproxyd component of PAN-OS allows authenticated administrators to disrupt services by issuing a specific command.
This issue affects PAN-OS 9.1 versions earlier than 9.1.3, while PAN-OS 8.1, PAN-OS 9.0, and Prisma Access services are not impacted.

The Impact of CVE-2020-2031

CVSS Base Score: 4.9 (Medium Severity)
Attack Vector: Network
Availability Impact: High
Privileges Required: High
The vulnerability can lead to denial of service by restarting the device and putting it into maintenance mode.

Technical Details of CVE-2020-2031

This section covers the specific technical aspects of the vulnerability.

Vulnerability Description

An integer underflow vulnerability in the dnsproxyd component of the PAN-OS management interface.
Authenticated administrators can trigger the vulnerability through a command, causing service disruption.

Affected Systems and Versions

Affected: PAN-OS 9.1 custom version less than 9.1.3
Unaffected: PAN-OS 9.0., 8.1.

Exploitation Mechanism

Authenticated administrators can exploit the vulnerability by issuing a specific command via the command line interface.

Mitigation and Prevention

Steps to address and prevent the CVE-2020-2031 vulnerability.

Immediate Steps to Take

Upgrade to PAN-OS 9.1.3 or later versions to mitigate the vulnerability.
Follow best practices for securing the PAN-OS management interface.

Long-Term Security Practices

Regularly update PAN-OS to the latest versions to ensure security patches are applied.
Conduct security reviews and audits to identify and address potential vulnerabilities.

Patching and Updates

The issue is resolved in PAN-OS 9.1.3 and all subsequent versions.