Check Point Advisories

Apple Safari WebKit JSString Use After Free Code Execution (CVE-2017-2491)

Vulnerability
Protection

Check Point Reference:	CPAI-2017-0402
Date Published:	10 May 2017
Severity:	High
Last Updated:	Wednesday 10 May, 2017
Source:
Industry Reference:	CVE-2017-2491
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?
Vulnerability Description	Safari is a web browsing application developed by Apple. Safari browsing functionality is built around the set of components called WebKit. WebKit is a development toolkit which allows third party developers to build applications that use Internet technologies such as HTML, HTTP, and others. A use-after-free vulnerability exists in Apple Safari's WebKit. The vulnerability is due to lack of validation of an String object's existence prior to accessing its replace() method. To trigger this issue, an attacker may create a malicious web page and persuade a user to view it. Successful exploitation of this vulnerability will allow an attacker to execute code under the context of the current process.

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 Apple Safari WebKit JSString Use After Free Code Execution 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: Web Client Enforcement Violation.
Attack Information: Apple Safari WebKit JSString Use After Free Code Execution