MS-ISAC CYBERSECURITY ADVISORIES

MS-ISAC ADVISORY NUMBER:
2016-076

DATE(S) ISSUED:
5/10/2016

SUBJECT:
Multiple Vulnerabilities in Microsoft Office Could Allow for Remote Code Execution (MS16-054)

OVERVIEW:

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. An attacker who successfully exploited these vulnerabilities could run arbitrary code in the context of the current 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 currently no reports of these vulnerabilities being exploited in the wild.


SYSTEMS AFFECTED:

  • Microsoft Office 2007
  • Microsoft Office 2013
  • Microsoft Office 2013 RT
  • Microsoft Office 2016
  • Microsoft Office for Mac 2011
  • Microsoft Office 2016 for Mac
  • Microsoft Word View
  • Microsoft Office Compatibility Pack Service Pack 3
  • Microsoft SharePoint Server 2010
  • Microsoft Office Web Apps 2010

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 Office, the most severe of which could allow for remote code execution if a user opens a specially crafted Microsoft Office file. An attacker who successfully exploited these vulnerabilities could run arbitrary code in the context of the current 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.

 

  • Three remote code execution vulnerabilities exist in Microsoft Office software when the Office software fails to properly handle objects in memory (CVE-2016-0126, CVE-2016-0140, CVE-2016-0198).

  • A remote code execution vulnerability exists when the Windows font library improperly handles specially crafted embedded fonts (CVE-2016-0183).

 

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 un-trusted websites or follow links provided by unknown or un-trusted sources.

  • Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from un-trusted sources.

  • Microsoft has a list of registry modifications which may be used as a workaround to implementing this patch for Office 2007 and 2013 at the Microsoft reference linked below.

REFERENCES:

Microsoft:
https://technet.microsoft.com/en-us/library/security/ms16-054.aspx

CVE:
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-0126
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-0140
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-0183
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-0198