Remote DoS when processing RPZ rules in ISC BIND

1) Improper input validation

EUVDB-ID: #VU7091

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-2017-3140

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 an error when processing Response Policy Zones (RPZ) rules, when NSDNAME or NSIP policy rules are used. A remote attacker can trigger the affected server to enter an endless loop and repeatedly query a set of authoritative nameservers.

Successful exploitation of the vulnerability may allow an attacker to perform a denial of service attack.

Mitigation

Update to version 9.9.10-P1, 9.10.5-P1 or 9.11.1-P1.

Vulnerable software versions

ISC BIND: 9.9.10 - 9.11.1

External links

http://kb.isc.org/article/AA-01495/74/CVE-2017-3140%3A-An-error-processing-RPZ-rules-can-cause-name...

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.