Arch Linux Security Advisory ASA-202010-6
========================================
Severity: High
Date    : 2020-10-18
CVE-ID  : CVE-2020-25829
Package : powerdns-recursor
Type    : denial of service
Remote  : Yes
Link    : https://security.archlinux.org/AVG-1243

Summary
======
The package powerdns-recursor before version 4.3.5-1 is vulnerable to
denial of service.

Resolution
=========
Upgrade to 4.3.5-1.

# pacman -Syu "powerdns-recursor>=4.3.5-1"

The problem has been fixed upstream in version 4.3.5.

Workaround
=========
None.

Description
==========
An issue has been found in PowerDNS Recursor before 4.3.5 where 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).

Impact
=====
A remote attacker can deny DNSSEC validation by updating the state of
cached entries.

References
=========
https://www.openwall.com/lists/oss-security/2020/10/13/3
https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2020-07.html
https://downloads.powerdns.com/patches/2020-07/any-cache-update-4.3.4.diff
https://github.com/PowerDNS/pdns/commit/ae33c53e68a32189e0a2fd3df24821d3edce4503
https://security.archlinux.org/CVE-2020-25829