Denial of service in PowerDNS Authoritative Server

1) Input validation error

EUVDB-ID: #VU18151

Risk: Medium

CVSSv3.1: 6.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2019-3871

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input when processing DNS requests in RESTful mode in the HTTP Connector of the Remote backend. A remote attacker can send a specially crafted DNS request to the affected server and perform denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

PowerDNS: 2.0 - 4.1.6

External links

http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00022.html
http://www.openwall.com/lists/oss-security/2019/03/18/4
http://www.securityfocus.com/bid/107491
http://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3871
http://doc.powerdns.com/authoritative/security-advisories/powerdns-advisory-2019-03.html
http://lists.debian.org/debian-lts-announce/2019/03/msg00039.html
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GWUHF6MRSQ3YO7UUISGLV7MXCAGBW2VD/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ROFI6OTWF4GKONNSNEDUCW6LVSSEBZNF/
http://seclists.org/bugtraq/2019/Apr/8
http://www.debian.org/security/2019/dsa-4424

Q & A

Can this vulnerability be exploited remotely?

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

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.