MS-ISAC CYBERSECURITY ADVISORIES

MS-ISAC ADVISORY NUMBER:
2016-170

DATE(S) ISSUED:
11/08/2016

SUBJECT:
Multiple Vulnerabilities in Microsoft Office Could Allow for Remote Code Execution (MS16-133)

OVERVIEW:

Multiple vulnerabilities have been discovered in Microsoft Office, the most severe of which could result in remote code execution if the user opens a specially crafted Microsoft Office file. 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:

There are no reports of these vulnerabilities being exploited in the wild.

SYSTEMS AFFECTED:

• Microsoft Office 2007, 2010, 2013, 2013 RT, 2016

• Microsoft Office for Mac 2011, Office 2016 for Mac

• Microsoft Office Compatibility Pack SP3

• Microsoft Excel Viewer

• Microsoft PowerPoint Viewer

• Microsoft Word Viewer

• Microsoft SharePoint Server 2010, 2013

• Microsoft Office Web Apps 2010, 2013

RISK:

Government:

• Large and medium government entities:High

• Small government: Medium

Businesses:

• Large and medium business entities:High

• Small business entities:Medium

Home users: Low

TECHNICAL SUMMARY:

Multiple vulnerabilities have been discovered in Microsoft Office, the most severe of which could allow for remote code execution if a user opens a specially crafted Microsoft Office file.

• Ten memory corruption vulnerabilities exist when Microsoft Office fails to properly handle objects in memory. (CVE-2016-7213, CVE-2016-7228, CVE-2016-7229, CVE-2016-7230, CVE-2016-7231, CVE-2016-7232, CVE-2016-7234, CVE-2016-7235, CVE-2016-7236, CVE-2016-7245)

• A denial of service vulnerability exists when a user opens a specially crafted file. (CVE-2016-7244)

• An information disclosure vulnerability exists when Office or Word reads out of bound memory. (CVE-2016-7233)

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 provided by Microsoft to vulnerable systems 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/en-us/library/security/ms16-133.aspx

CVE:

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7213

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7228

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7229

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7230

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7231

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7232

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7233

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7234

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7235

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7236

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7244

http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7245