Description
An issue has been found in the parsing of authoritative answers in PowerDNS Recursor before 4.0.8, leading to a NULL pointer dereference when parsing a specially crafted answer containing a CNAME of a different class than IN. An unauthenticated remote attacker could cause a denial of service.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| PowerDNS | pdns-recursor | 4.0.8 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | pdns-recursor | 4.1.0-1 | — |
| Debian 13 | pdns-recursor | 4.1.0-1 | — |
| Debian 12 | pdns-recursor | 4.1.0-1 | — |
| Debian 9 | pdns-recursor | 4.0.4-1+deb9u3 | DSA-4063-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | pdns-recursor | No fix yet | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
-
shutingrz/CVE-2017-15120_PoC ★ 0 · Oct 16, 2018
PowerDNS CVE-2017-15120 / DO NOT ABUSE
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- DSA-4063-1 pdns-recursor - security update Debian Security (DSA / DLA) · Mar 9, 2026