CVE-2018-16855 Memory corruption in pdns-recursor
A remote attacker can cause a denial of service in PowerDNS Recursor by triggering an out-of-bounds memory read during DNS query processing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2018-16855?
CVE-2018-16855 is a high-severity memory corruption vulnerability in Powerdns Recursor, published on 3 Dec 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An issue has been found in PowerDNS Recursor before version 4.1.8 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.
Weakness: CWE-125
Which versions are affected by CVE-2018-16855?
It affects 1 product.
Products include Powerdns Recursor.
How do I fix CVE-2018-16855?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2018-16855 being exploited?
There is no known exploitation of CVE-2018-16855 in the wild and no public exploit code.
Other vulnerabilities in Powerdns Recursor
- CVE-2009-4009 Memory corruption in n/a
- CVE-2020-10030 Memory corruption in n/a
- CVE-2025-59023 Crafted delegations or IP fragments can poison cached delegations in Recursor
- CVE-2025-59030 Insufficient validation of incoming notifies over TCP can lead to a denial of service in Recursor
- CVE-2023-22617 Denial of service in n/a
Sources
Also known as DEBIAN-CVE-2018-16855, GHSA-qx96-6995-fgrp, UBUNTU-CVE-2018-16855.