An issue has been found in PowerDNS Authoritative Server allowing an authorized user to crash the server by inserting a specially crafted record in a zone under their control then sending a DNS query for that record. The issue is due to an integer overflow when checking if the content of the record matches the expected size, allowing an attacker to cause a read past the buffer boundary. This issue has been assigned CVE-2016-2120.
PowerDNS Authoritative Server up to and including 3.4.10 and 4.0.1 are affected. The PowerDNS Recursor is not affected.
For those unable to upgrade to a new version, a minimal patch is available
We would like to thank Mathieu Lafon for finding and subsequently reporting this issue.