Description
An issue has been found in PowerDNS Recursor 4.1.0 through 4.3.0 where records in the answer section of a NXDOMAIN response lacking an SOA were not properly validated in SyncRes::processAnswer, allowing an attacker to bypass DNSSEC validation.
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 | 4.3.1-1 | — |
| Debian 13 | pdns-recursor | 4.3.1-1 | — |
| Debian 12 | pdns-recursor | 4.3.1-1 | — |
| Debian 10 | pdns-recursor | 4.1.11-1+deb10u1 | DSA-4691-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | pdns-recursor | No fix yet | — |
| Ubuntu Pro 18.04 LTS | pdns-recursor | No fix yet | — |
| Ubuntu Pro 16.04 LTS | pdns-recursor | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP1 | pdns-recursor | 4.1.12-bp151.4.3.1 | openSUSE-SU-2020:0698-1 |
| SUSE Package Hub 12 SP1 | pdns-recursor | 4.1.12-bp151.4.3.1 | openSUSE-SU-2020:0698-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | pdns-recursor | 4.5.5-1.3 | openSUSE-SU-2024:11157-1 |
| openSUSE Leap 15.1 | pdns-recursor | 4.1.12-bp151.4.3.1 | openSUSE-SU-2020:0698-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.23 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.22 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.21 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.20 | pdns-recursor | 4.3.1-r0 | — |
Show 11 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.18 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.17 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.16 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.15 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.14 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.13 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.12 | pdns-recursor | 4.3.1-r0 | — |
| Alpine v3.11 | pdns-recursor | 4.2.2-r0 | — |
| Alpine v3.10 | pdns-recursor | 4.1.16-r0 | — |
| Alpine v3.9 | pdns-recursor | 4.1.16-r0 | — |
Advisories 3
- DSA-4691-1 pdns-recursor - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:11157-1 pdns-recursor-4.5.5-1.3 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:0698-1 Security update for pdns-recursor SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://doc.powerdns.com/recursor/security-advisories/powerdns-advisory-2020-02.html
- [oss-security] 20200519 PowerDNS Recursor 4.3.1, 4.2.2. and 4.1.16 released fixing multiple vulnerabilities mailing-list
- DSA-4691 vendor-advisory
- openSUSE-SU-2020:0698 vendor-advisory
- FEDORA-2020-d9abb0c06d vendor-advisory
- FEDORA-2020-c0ff3df740 vendor-advisory