CVE-2019-3806 Explained : Impact and Mitigation
Learn about CVE-2019-3806 affecting PowerDNS Recursor versions after 4.1.3 before 4.1.9. Understand the impact, technical details, and mitigation steps to prevent Lua hooks bypass.
PowerDNS Recursor versions after 4.1.3 before 4.1.9 are affected by a vulnerability related to Lua hooks not being correctly implemented for TCP-based queries, potentially allowing bypassing of Lua-enforced security policies.
Understanding CVE-2019-3806
This CVE involves a specific issue in PowerDNS Recursor versions that could lead to security policy bypass.
What is CVE-2019-3806?
The vulnerability in PowerDNS Recursor versions after 4.1.3 but before 4.1.9 allows for potential bypassing of Lua-enforced security policies due to incorrect implementation of Lua hooks for TCP-based queries under certain settings.
The Impact of CVE-2019-3806
The impact of this CVE is rated as MEDIUM with a CVSS base score of 5.4. The vulnerability requires low privileges and user interaction, with high availability impact.
Technical Details of CVE-2019-3806
This section provides more technical insights into the CVE.
Vulnerability Description
The issue arises from Lua hooks not being properly applied to TCP queries in specific settings, potentially enabling security policy circumvention.
Affected Systems and Versions
- Product: PowerDNS Recursor
- Vendor: Power DNS
- Versions Affected: versions after 4.1.3 before 4.1.9
Exploitation Mechanism
The vulnerability can be exploited by manipulating TCP-based queries under certain specific settings to bypass Lua-enforced security policies.
Mitigation and Prevention
Protecting systems from CVE-2019-3806 is crucial. Here are some steps to mitigate and prevent exploitation.
Immediate Steps to Take
- Update PowerDNS Recursor to version 4.1.9 or later to eliminate the vulnerability.
- Monitor network traffic for any suspicious activities that could indicate exploitation.
Long-Term Security Practices
- Regularly update and patch all software to prevent known vulnerabilities.
- Implement network segmentation and access controls to limit the impact of potential breaches.
Patching and Updates
- Stay informed about security advisories from PowerDNS and apply patches promptly to secure systems.