Unbound before 1.10.1 has Insufficient Control of Network Message Volume, aka an "NXNSAttack" issue. This is triggered by random subdomains in the NSDNAME in NS records.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-12662
• https://lists.debian.org/debian-lts-announce/2021/02/msg00017.html
• https://lists.fedoraproject.org/archives/list/[email protected]/message/F5NFROI2OMCZLYRTCNGHGO3TUD32LCIQ/
• https://lists.fedoraproject.org/archives/list/[email protected]/message/YJ42N2HBZ3DXMSEC56SWIIOFQGOS5M7I/
• https://nlnetlabs.nl/downloads/unbound/CVE-2020-12662_2020-12663.txt
• https://security.FreeBSD.org/advisories/FreeBSD-SA-20:19.unbound.asc
• https://security.netapp.com/advisory/ntap-20200702-0006/
• https://usn.ubuntu.com/4374-1/
• https://www.debian.org/security/2020/dsa-4694
• https://www.synology.com/security/advisory/Synology_SA_20_12
• http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00067.html
• http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00069.html
• http://www.nxnsattack.com
• http://www.openwall.com/lists/oss-security/2020/05/19/5