Check Point Advisories

ISC BIND Referral CNAME and DNAME Assertion Failure Denial of Service (CVE-2017-3137)

Vulnerability
Protection

Check Point Reference:	CPAI-2017-0474
Date Published:	7 Jun 2017
Severity:	Medium
Last Updated:	Monday 22 January, 2018
Source:	ISC AA-01466
Industry Reference:	CVE-2017-3137
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	ISC BIND 9.10.4-P6 ISC BIND 9.10.5b1->9.10.5rc2 ISC BIND 9.11.0-P3 ISC BIND 9.11.1b1->9.11.1rc2 ISC BIND 9.9.10b1->9.9.10rc1 ISC BIND 9.9.9-P6 ISC BIND 9.9.9-S8
Vulnerability Description	A denial of service vulnerability exists in ISC BIND9. The vulnerability is due to improper handling of responses containing CNAME and DNAME records after receiving a referral. A remote attacker could exploit this vulnerability by providing two specially crafted responses to the server.

Protection Overview

This protection detects attempts to exploit this vulnerability.

In order for the protection to be activated, update your Security Gateway product to the latest IPS update. For information on how to update IPS, go to SBP-2006-05, click on Protection tab and select the version of your choice.

Security Gateway R80 / R77 / R75

In the IPS tab, click Protections and find the ISC BIND Referral CNAME and DNAME Assertion Failure Denial of Service protection using the Search tool and Edit the protection's settings.
Install policy on all Security Gateways.

This protection's log will contain the following information:

Attack Name: DNS Enforcement Violation.
Attack Information: ISC BIND Referral CNAME and DNAME Assertion Failure Denial of Service