CVE-2020-10995 Information

Description

PowerDNS Recursor from 4.1.0 up to and including 4.3.0 does not sufficiently defend against amplification attacks. An issue in the DNS protocol has been found that allow malicious parties to use recursive DNS services to attack third party authoritative name servers. The attack uses a crafted reply by an authoritative name server to amplify the resulting traffic between the recursive and other authoritative name servers. Both types of service can suffer degraded performance as an effect. This is triggered by random subdomains in the NSDNAME in NS records. PowerDNS Recursor 4.1.16 4.2.2 and 4.3.1 contain a mitigation to limit the impact of this DNS protocol issue.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Reference

http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00052.html http://www.nxnsattack.com https://doc.powerdns.com/recursor/security-advisories/powerdns-advisory-2020-01.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

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

7.5