Resource exhaustion in PowerDNS - CVE-2016-7068

Detailed vulnerability description

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

An issue has been found in PowerDNS before 3.4.11 and 4.0.2, and PowerDNS recursor before 3.7.4 and 4.0.4, allowing a remote, unauthenticated attacker to cause an abnormal CPU usage load on the PowerDNS server by sending crafted DNS queries, which might result in a partial denial of service if the system becomes overloaded. This issue is based on the fact that the PowerDNS server parses all records present in a query regardless of whether they are needed or even legitimate. A specially crafted query containing a large number of records can be used to take advantage of that behaviour.

How to mitigate CVE-2016-7068

Sources

• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-7068
• https://doc.powerdns.com/md/security/powerdns-advisory-2016-02/
• https://www.debian.org/security/2017/dsa-3763
• https://www.debian.org/security/2017/dsa-3764