PowerDNS Security Advisory 2018-09: Crafted query can cause a denial of service

• CVE: CVE-2018-16855
• Date: 26th of November 2018
• Affects: PowerDNS Recursor from 4.1.0 up to and including 4.1.7
• Not affected: 4.0.x, 4.1.8
• Severity: Medium
• Impact: Denial of service
• Exploit: This problem can be triggered via crafted queries
• Risk of system compromise: No
• Solution: Upgrade to a non-affected version

An issue has been found in PowerDNS Recursor where a remote attacker sending a DNS query can trigger an out-of-bounds memory read while computing the hash of the query for a packet cache lookup, possibly leading to a crash.

This issue has been assigned CVE-2018-16855 by Red Hat.

When the PowerDNS Recursor is run inside a supervisor like supervisord or systemd, a crash will lead to an automatic restart, limiting the impact to a somewhat degraded service.

PowerDNS Recursor from 4.1.0 up to and including 4.1.7 is affected.