MS-ISAC CYBERSECURITY ADVISORIES

MS-ISAC ADVISORY NUMBER:
2016-181

DATE(S) ISSUED:
12/13/2016

SUBJECT:
Cumulative Security Update for Internet Explorer (MS16-144)

OVERVIEW:

Multiple vulnerabilities have been discovered in Microsoft Internet Explorer, the most severe of which could allow remote code execution if a user views a specially crafted web page. Successful exploitation of these vulnerabilities could result in an attacker gaining the same privileges as the logged on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

THREAT INTELLIGENCE:

Three vulnerabilities have been publically disclosed (CVE-2016-7281, CVE-2016-7282, CVE-2016-7202). There are no reports of these vulnerabilities being exploited in the wild.

SYSTEMS AFFECTED:

· Internet Explorer 9, 10, 11

RISK:

Government:

· Large and medium government entities: High

· Small government entities: Medium

Businesses:

· Large and medium business entities: High

· Small business entities: Medium

Home users: Low

TECHNICAL SUMMARY:

Multiple vulnerabilities have been discovered in Microsoft Internet Explorer, the most severe of which that could allow remote code execution if a user views a specially crafted web page. Details of these vulnerabilities are as follows:

· Two remote code execution vulnerabilities exist when Microsoft Browsers improperly access objects in memory. (CVE-2016-7279, CVE-2016-7283)

· Three information disclosure vulnerabilities exist in the way Internet Explorer handle objects in memory. (CVE-2016-7278, CVE-2016-7282, CVE-2016-7284)

· A security feature bypass vulnerability exists when the Microsoft Browsers fails to correctly apply Same Origin Policy for scripts running inside Web Workers. (CVE-2016-7281)

· Two remote code execution vulnerabilities exist in the way affected Microsoft scripting engines render when handling objects in memory in Microsoft browsers. (CVE-2016-7202, CVE-2016-7287)

Successful exploitation of these vulnerabilities could result in an attacker gaining the same privileges as the logged on user. Depending on the privileges associated with the user, an attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

RECOMMENDATIONS:

We recommend the following actions be taken:

· Apply appropriate patches by Microsoft immediately after appropriate testing.

· Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack.

· Remind users not to visit websites or follow links provided by unknown or untrusted sources.

· Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from untrusted sources.

· Apply the Principle of Least Privilege to all systems and services.

REFERENCES:

Microsoft:

https://technet.microsoft.com/library/security/MS16-144

CVE:

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7202

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7278

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7279

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7281

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7282

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7283

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7284

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7287