Cache poisoning in PowerDNS Recursor

Published: 2020-10-13
Risk Medium
Patch available YES
Number of vulnerabilities 1
CVE-ID CVE-2020-25829
Exploitation vector Network
Public exploit N/A
Vulnerable software
PowerDNS Recursor
Server applications / DNS servers

Vendor PowerDNS.COM B.V.

Security Bulletin

This security bulletin contains one medium risk vulnerability.

1) Input validation error

EUVDB-ID: #VU47532

Risk: Medium


CVE-ID: CVE-2020-25829


Exploit availability:


The vulnerability allows a remote attacker to perform cache poisoning attack.

The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can cause the cached records for a given name to be updated to the ‘Bogus’ DNSSEC validation state, instead of their actual DNSSEC ‘Secure’ state, via a DNS ANY query. This results in a denial of service for installations that always validate (dnssec=validate) and for clients requesting validation when on-demand validation is enabled (dnssec=process).


Install updates from vendor's website.

Vulnerable software versions

PowerDNS Recursor: 4.0.0 - 4.4.0 alpha1

Fixed software versions

CPE2.3 External links

Q & A

Can this vulnerability be exploited remotely?

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Is there known malware, which exploits this vulnerability?