CVE-2019-3807 : Vulnerability Insights and Analysis

A problem has been discovered in versions 4.1.x before 4.1.9 of the PowerDNS Recursor, allowing attackers to bypass DNSSEC validation.

Understanding CVE-2019-3807

This CVE involves incorrect validation of records in the response's answer section from authoritative servers without the AA flag set.

What is CVE-2019-3807?

The vulnerability in PowerDNS Recursor versions 4.1.x before 4.1.9 allows attackers to circumvent DNSSEC validation by exploiting incorrect record validation.

The Impact of CVE-2019-3807

CVSS Base Score: 3.7 (Low Severity)
Attack Vector: Network
Attack Complexity: High
User Interaction: Required
Confidentiality Impact: Low
Integrity Impact: Low
Privileges Required: Low
Scope: Unchanged
Vector String: CVSS:3.0/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N
CWE ID: CWE-345

Technical Details of CVE-2019-3807

Vulnerability Description

The issue arises from the incorrect validation of records in responses from authoritative servers without the AA flag set, enabling attackers to bypass DNSSEC validation.

Affected Systems and Versions

Affected Product: pdns-recursor
Vendor: Power DNS
Affected Versions: versions 4.1.x before 4.1.9

Exploitation Mechanism

Attackers can exploit this vulnerability by manipulating records in the answer section of responses from authoritative servers without the AA flag set.

Mitigation and Prevention

Immediate Steps to Take

Update PowerDNS Recursor to version 4.1.9 or later.
Monitor for any suspicious DNS activities.

Long-Term Security Practices

Implement DNSSEC to enhance DNS security.
Regularly review and update DNS server configurations.

Patching and Updates

Apply patches provided by Power DNS to address this vulnerability.