MS-ISAC CYBERSECURITY ADVISORIES

MS-ISAC ADVISORY NUMBER:
2017-002

DATE(S) ISSUED:
01/10/2017

SUBJECT:
A Vulnerability in Microsoft Office Could Allow for Remote Code Execution

OVERVIEW:

A vulnerability has been discovered in Microsoft Office, which could result in remote code execution if a user opens a specially crafted Microsoft Office file. Successful exploitation of this vulnerability 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 currently no reports of this vulnerability being exploited in the wild.

SYSTEMS AFFECTED:

• Microsoft Office 2016

• Microsoft SharePoint Enterprise Server 2016

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:

A vulnerability has been discovered in Microsoft Office, which could result in remote code execution if a user opens a specially crafted Microsoft Office file. In an email attack scenario an attacker could exploit the vulnerability by sending the specially crafted file to the user and convincing the user to open the file. In a web-based attack scenario an attacker could host a website (or leverage a compromised website) that contains a specially crafted file that is designed to exploit the vulnerability. Note that the Preview Pane is not an attack vector for this vulnerability.

Successful exploitation of this vulnerability 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 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.

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

REFERENCES:

Microsoft:
https://technet.microsoft.com/en-us/security/bulletin/ms17-002

CVE:
http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-0003