Resource exhaustion in pdns-recursor (Alpine package)

1) Resource exhaustion

EUVDB-ID: #VU32136

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 - Resource exhaustion

Exploit availability: No

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

pdns-recursor (Alpine package): 4.0.3-r2

External links

http://git.alpinelinux.org/aports/commit/?id=3a479b103eb9d61f344de80e8293bbc27403ce40
http://git.alpinelinux.org/aports/commit/?id=e98a3138ba6fb05dfcce66ffb9974e77777486ad

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.