CVE-2017-15093 : Security Advisory and Response

PowerDNS Recursor versions 4.x up to 4.0.6 and 3.x up to 3.7.4 are vulnerable to unauthorized modification of Access Control List (ACL) and configuration of forward zones when api-config-dir is set to a non-empty value.

Understanding CVE-2017-15093

In this CVE, an authenticated user can manipulate the ACL and configure forward zones due to inadequate validation of netmask and IP addresses.

What is CVE-2017-15093?

PowerDNS Recursor versions 4.x up to 4.0.6 and 3.x up to 3.7.4 allow authorized users to modify ACL and configure forward zones when api-config-dir is set to a non-empty value. This can lead to injection of new configuration directives into the Recursor's configuration.

The Impact of CVE-2017-15093

The vulnerability enables authenticated users to manipulate ACL and configure forward zones, potentially leading to unauthorized access and configuration changes.

Technical Details of CVE-2017-15093

PowerDNS Recursor vulnerability details:

Vulnerability Description

Authorized users can update ACL and configure forward zones by adding and removing netmasks.
Inadequate validation of netmask and IP addresses allows injection of new configuration directives.

Affected Systems and Versions

Product: PowerDNS Recursor
Vendor: PowerDNS
Affected Versions: 4.x up to and including 4.0.6, 3.x up to and including 3.7.4

Exploitation Mechanism

An authenticated user can exploit the vulnerability by manipulating ACL and configuring forward zones when api-config-dir is set to a non-empty value.

Mitigation and Prevention

Protect your systems from CVE-2017-15093 with the following steps:

Immediate Steps to Take

Update PowerDNS Recursor to a patched version.
Restrict access to the API and configuration directories.
Monitor ACL and configuration changes for unauthorized modifications.

Long-Term Security Practices

Regularly review and update access control policies.
Conduct security audits to identify and address vulnerabilities.

Patching and Updates

Apply patches provided by PowerDNS to address the vulnerability.