Vulnerability identifier: #VU32136

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2016-7068

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
PowerDNS
Server applications / DNS servers

Vendor: PowerDNS.COM B.V.

Description

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

An issue has been found in PowerDNS before 3.4.11 and 4.0.2, and PowerDNS recursor before 3.7.4 and 4.0.4, 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.

Mitigation
Install update from vendor's website.

Vulnerable software versions

PowerDNS: 3.4.0 - 3.7.3

---

External links
http://bugzilla.redhat.com/show_bug.cgi?id=CVE-2016-7068
http://doc.powerdns.com/md/security/powerdns-advisory-2016-02/
http://www.debian.org/security/2017/dsa-3763
http://www.debian.org/security/2017/dsa-3764

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.