We’ve released PowerDNS Recursor 4.1.8.
This release fixes Security Advisory 2018-09 that we recently discovered, affecting PowerDNS Recursor from 4.1.0 up to and including 4.1.7. PowerDNS Recursor 4.0.x and below are not affected.
The issue is that a remote attacker can trigger an out-of-bounds memory read via a crafted query, while computing the hash of the query for a packet cache lookup, possibly leading to a crash.
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.
A minimal patch is available at https://downloads.powerdns.com/patches/2018-09/.
- #7221: Crafted query can cause a denial of service (CVE-2018-16855)