Arch Linux Security Advisory ASA-201811-13
=========================================
Severity: Medium
Date    : 2018-11-12
CVE-ID  : CVE-2018-10851 CVE-2018-14626 CVE-2018-14644
Package : powerdns-recursor
Type    : denial of service
Remote  : Yes
Link    : https://security.archlinux.org/AVG-805

Summary
======
The package powerdns-recursor before version 4.1.5-1 is vulnerable to
denial of service.

Resolution
=========
Upgrade to 4.1.5-1.

# pacman -Syu "powerdns-recursor>=4.1.5-1"

The problems have been fixed upstream in version 4.1.5.

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

Description
==========
- CVE-2018-10851 (denial of service)

An issue has been found in PowerDNS Authoritative Server before 4.1.5
and PowerDNS Recursor before 4.1.5. The issue is due to the fact that
some memory is allocated before the parsing and is not always properly
released if the record is malformed.
In the authoritative server case, it allows an authorized user to cause
a memory leak by inserting a specially crafted record in a zone under
their control, then sending a DNS query for that record. In the case of
the recursor, it allows a malicious authoritative server to cause a
memory leak by sending specially crafted records.

- CVE-2018-14626 (denial of service)

An issue has been found in PowerDNS Authoritative Server before 4.1.5
and PowerDNS Recursor before 4.1.5, allowing a remote user to craft a
DNS query that will cause an answer without DNSSEC records to be
inserted into the packet cache and be returned to clients asking for
DNSSEC records, thus hiding the presence of DNSSEC signatures for a
specific qname and qtype. For a DNSSEC-signed domain, this means that
DNSSEC validating clients will consider the answer to be bogus until it
expires from the packet cache, leading to a denial of service.

- CVE-2018-14644 (denial of service)

An issue has been found in PowerDNS Recursor before 4.1.5 where a
remote attacker sending a DNS query for a meta-type like OPT can lead
to a zone being wrongly cached as failing DNSSEC validation. It only
arises if the parent zone is signed, and all the authoritative servers
for that parent zone answer with FORMERR to a query for at least one of
the meta-types. As a result, subsequent queries from clients requesting
DNSSEC validation will be answered with a ServFail.

Impact
=====
A remote attacker authorized to send queries can force the recursor to
serve answers without DNSSEC-related records to DNSSEC-enabled queries,
or can trick the recursor into thinking an authoritative server does
not handle EDNS correctly, causing validation failures. A remote
attacker authorized to send queries and controlling a malicious
authoritative server can crash the recursor by making it send queries
to their server then replying with crafted answers.

References
=========
https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2018-04.html
https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2018-06.html
https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2018-07.html
https://docs.powerdns.com/authoritative/security-advisories/powerdns-advisory-2018-03.html
https://docs.powerdns.com/authoritative/security-advisories/powerdns-advisory-2018-05.html
https://security.archlinux.org/CVE-2018-10851
https://security.archlinux.org/CVE-2018-14626
https://security.archlinux.org/CVE-2018-14644