Check Point Advisories

OpenVPN read_key Stack Based Buffer Overflow (CVE-2017-12166)

Vulnerability
Protection

Check Point Reference:	CPAI-2017-0835
Date Published:	15 Oct 2017
Severity:	Medium
Last Updated:	Monday 23 October, 2017
Source:	OpenVPN
Industry Reference:	CVE-2017-12166
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	OpenVPN Project OpenVPN 2.3.x prior to 2.3.18 OpenVPN Project OpenVPN 2.4.x prior to 2.4.4
Vulnerability Description	A stack-based buffer overflow vulnerability exists in OpenVPN. The vulnerability is due to a lack of bounds check on the length of key and HMAC lengths provided by the client. A remote, unauthenticated attacker can exploit this vulnerability by sending a crafted P_CONTROL_V1 message to a target 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 OpenVPN read_key Stack Based Buffer Overflow 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: SSL Enforcement Violation.
Attack Information: OpenVPN read_key Stack Based Buffer Overflow