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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-12244
• https://doc.powerdns.com/recursor/security-advisories/powerdns-advisory-2020-02.html
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NMP72NJGKBWR5WEBXAWX5KSLQUDFTG6S/
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PS4ZN5XGENYNFKX7QIIOUCQQHXE37GJF/
• https://www.debian.org/security/2020/dsa-4691
• http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00052.html
• http://www.openwall.com/lists/oss-security/2020/05/19/3