MS-ISAC CYBERSECURITY ADVISORIES

MS-ISAC ADVISORY NUMBER:
2016-115

DATE(S) ISSUED:
08/09/2016

SUBJECT:
Cumulative Security Update for Internet Explorer (MS16-095)

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. An attacker who successfully exploited these vulnerabilities could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

THREAT INTELLIGENCE:
There are currently no reports of this vulnerability being exploited in the wild.

SYSTEMS AFFECTED:
· Internet Explorer 9

· Internet Explorer 10

· Internet Explorer 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:
Microsoft Internet Explorer is prone to multiple vulnerabilities that could allow remote code execution. The vulnerabilities are as follows:
· Five memory corruption vulnerabilities exist when Internet Explorer improperly accesses objects in memory (CVE-2016-3288, CVE-2016-3289, CVE-2016-3290, CVE-2016-3293, CVE-2016-3322)

· Two information disclosure vulnerabilities exist when Internet Explorer improperly handles page content (CVE-2016-3321, CVE-2016-3329)

· Two information disclosure vulnerabilities exist when Internet Explorer improperly handles objects in memory (CVE-2016-3326, CVE-2016-3327)

The most severe of these vulnerabilities could allow an attacker to execute remote code by luring a victim to visit a specially crafted malicious website. If the current user is logged on with administrative user rights, an attacker could take control of an affected system. 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.

RECOMMENDATIONS:
We recommend the following actions be taken:
· Apply appropriate patches by Microsoft immediately after appropriate testing.

· 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.

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

REFERENCES:

Microsoft:
https://technet.microsoft.com/library/security/MS16-095

CVE:
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3288
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3289
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3290
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3293
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3321
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3322
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3326
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3327
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3329