Updates released for the authoritative nameserver and recursive nameserver components of PowerDNS patch several vulnerabilities that can be exploited for denial-of-service (DoS) attacks, records manipulation, modifying configurations, and cross-site scripting (XSS) attacks.
PowerDNS Recursor versions 4.0.0 through 4.0.6 are affected by a DNSSEC validation issue that can be exploited by a man-in-the-middle (MitM) attacker to forge signatures and alter DNS records (CVE-2017-15090).
Another flaw affecting these versions of Recursor is CVE-2017-15092, an XSS bug that allows a remote attacker to inject arbitrary HTML and JavaScript code into the Recursor web interface. The security hole can be exploited by sending specially crafted DNS queries to the server in order to alter the web interface or cause it to enter a DoS condition.
The Recursor is also impacted by a vulnerability that allows an authenticated attacker to inject new directives into its configuration (CVE-2017-15093). The last issue affecting this component is a DoS flaw caused by a memory leak that can occur when parsing specially crafted DNSSEC ECDSA keys (CVE-2017-15094). The vulnerability can be exploited by using an authoritative server to send specially crafted keys to the recursor.
The only security hole affecting PowerDNS Authoritative versions 4.0.4, 3.4.11 and prior is CVE-2017-15091, which allows an authenticated attacker to cause a DoS condition.
The vulnerabilities have been rated medium and low severity as they do not impact default configurations. Patches are included in PowerDNS Authoritative 4.0.5 and Recursor 4.0.7. Minimal fixes have also been provided for the 3.4.11 and 3.7.4 releases, but users of these versions have been advised to migrate to the 4.x branch.
These security holes were discovered by Finland-based cybersecurity services company Nixu during a source code audit, Chris Navarrete of Fortinet’s Fortiguard Labs, Kees Monshouwer, and a researcher who uses the online moniker “everyman.”
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