CVE-2020-10995
mediumpriority · track · 32EPSS 0.045 · 91 %ileDEEUUSEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (38)
Products and version ranges known to be affected.
- Avaya Aura Application Enablement Servicesall versionscert_bundDEcpe:/a:avaya:aura_application_enablement_services:-
advisories (1)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2024-0978Mehrere DNS Server: Schwachstelle ermöglicht Denial of ServiceDeutsch2020-05-19csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in mehreren DNS Server Produkten ausnutzen, um einen Denial of Service Angriff durchzuführen.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (21)
External citations — patches, advisories, analysis.
- http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00052.htmlcnnvd
- http://www.nxnsattack.comcnnvd
- https://doc.powerdns.com/recursor/security-advisories/powerdns-advisory-2020-01.htmlcnnvd
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NMP72NJGKBWR5WEBXAWX5KSLQUDFTG6S/cnnvd
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PS4ZN5XGENYNFKX7QIIOUCQQHXE37GJF/cnnvd
- https://media.cert.europa.eu/static/SecurityAdvisories/2020/CERT-EU-SA2020-027.pdfcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2020-10995cnnvd
- https://vigilance.fr/vulnerability/PowerDNS-Recursor-denial-of-service-via-Amplification-Attack-32323cnnvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan