Arch Linux Security Advisory ASA-201701-30
=========================================
Severity: Medium
Date    : 2017-01-19
CVE-ID  : CVE-2016-7068 CVE-2016-7073 CVE-2016-7074
Package : powerdns-recursor
Type    : multiple issues
Remote  : Yes
Link    : https://security.archlinux.org/AVG-148

Summary
======
The package powerdns-recursor before version 4.0.4-1 is vulnerable to
multiple issues including denial of service and insufficient
validation.

Resolution
=========
Upgrade to 4.0.4-1.

# pacman -Syu "powerdns-recursor>=4.0.4-1"

The problems have been fixed upstream in version 4.0.4.

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

Description
==========
- CVE-2016-7068 (denial of service)

An issue has been found in PowerDNS allowing a remote, unauthenticated
attacker to cause an abnormal CPU usage load on the PowerDNS server by
sending crafted DNS queries, which might result in a partial denial of
service if the system becomes overloaded. This issue is based on the
fact that the PowerDNS server parses all records present in a query
regardless of whether they are needed or even legitimate. A specially
crafted query containing a large number of records can be used to take
advantage of that behaviour.

- CVE-2016-7073 (insufficient validation)

An issue has been found in PowerDNS Authoritative Server and PowerDNS
Recursor allowing an attacker in position of man-in-the-middle to alter
the content of an AXFR because of insufficient validation of TSIG
signatures. A missing check of the TSIG time and fudge values in
AXFRRetriever, leading to a possible replay attack.

- CVE-2016-7074 (insufficient validation)

An issue has been found in PowerDNS Authoritative Server and PowerDNS
Recursor allowing an attacker in position of man-in-the-middle to alter
the content of an AXFR because of insufficient validation of TSIG
signatures. A missing check that the TSIG record is the last one,
leading to the possibility of parsing records that are not covered by
the TSIG signature.

Impact
=====
A remote attacker is able to perform a denial of service attack or
bypass certain verification possibly leading to a replay attack.

References
=========
https://seclists.org/oss-sec/2017/q1/97
https://doc.powerdns.com/md/security/powerdns-advisory-2016-02/
https://doc.powerdns.com/md/security/powerdns-advisory-2016-04/
https://security.archlinux.org/CVE-2016-7068
https://security.archlinux.org/CVE-2016-7073
https://security.archlinux.org/CVE-2016-7074