CVE-2020-25829 : Exploit Details and Defense Strategies

PowerDNS Recursor before 4.1.18, 4.2.x before 4.2.5, and 4.3.x before 4.3.5 allows a remote attacker to manipulate cached DNS records, leading to a denial of service.

Understanding CVE-2020-25829

This CVE involves a vulnerability in PowerDNS Recursor versions before 4.1.18, 4.2.x before 4.2.5, and 4.3.x before 4.3.5 that can be exploited by a remote attacker to disrupt DNSSEC validation.

What is CVE-2020-25829?

The vulnerability allows an attacker to change cached records to the Bogus DNSSEC validation state, causing denial of service for installations that validate always and for clients requesting validation with on-demand validation enabled.

The Impact of CVE-2020-25829

The exploitation of this vulnerability can lead to a denial of service for affected systems, impacting their DNSSEC validation processes.

Technical Details of CVE-2020-25829

PowerDNS Recursor vulnerability details and affected systems.

Vulnerability Description

Found in PowerDNS Recursor versions before 4.1.18, 4.2.x before 4.2.5, and 4.3.x before 4.3.5
Allows manipulation of cached records to Bogus DNSSEC validation state

Affected Systems and Versions

PowerDNS Recursor versions before 4.1.18, 4.2.x before 4.2.5, and 4.3.x before 4.3.5

Exploitation Mechanism

Attacker can trigger the issue via a DNS ANY query

Mitigation and Prevention

Protecting systems from CVE-2020-25829.

Immediate Steps to Take

Update PowerDNS Recursor to versions 4.1.18, 4.2.5, or 4.3.5
Disable DNSSEC validation if not required

Long-Term Security Practices

Regularly monitor for security advisories and updates
Implement network segmentation and access controls

Patching and Updates

Apply patches provided by PowerDNS to address the vulnerability