Multiple Vulnerabilities in Microsoft Office PowerPoint and Excel for Mac Could Allow for Remote Code Execution

ITS Advisory Number: 
2018-058
Date(s) Issued: 
Thursday, May 17, 2018
Subject: 
Multiple Vulnerabilities in Microsoft Office PowerPoint and Excel for Mac Could Allow for Remote Code Execution
Overview: 

Multiple vulnerabilities have been discovered in Microsoft Office PowerPoint and Excel for Mac, which could allow for remote code execution. Microsoft Office PowerPoint and Excel for Mac are office productivity software. 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 currently no reports of these vulnerabilities being exploited in the wild.

Systems Affected: 
  • Microsoft Office 2016 for Mac versions prior to 16.13.0

RISK
GOVERNMENT
Large and medium government entities: 
High
Small government entities: 
Medium
BUSINESS
Large and medium business entities: 
High
Small business entities: 
Medium
Home Users: 
Low
Description: 

Multiple vulnerabilities have been discovered in Microsoft Office PowerPoint and Excel for Mac, which could allow for remote code execution. These vulnerabilities occur when an attacker entices a victim to open a specially crafted file using the affected application where Microsoft Office PowerPoint and Excel for Mac fails to properly handle objects in memory.

 

In an email attack scenario, an attacker could exploit these vulnerabilities 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 accepts or hosts user-provided content) that contains a specially crafted file designed to exploit these vulnerabilities. An attacker would have no way to force users to visit the website. Instead, an attacker would have to convince users to click a link, typically by way of an enticement in an email or instant message, and then convince them to open the specially crafted file.

 

Details of these vulnerabilities are as follows:

  • Two remote code execution vulnerabilities exist when Microsoft Office Excel for Mac fails to properly handle objects in memory (CVE-2018-8147, CVE-2018-8162).

  • One remote code execution vulnerability exist when Microsoft Office PowerPoint for Mac fails to properly handle objects in memory (CVE-2018-8176).

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.

Actions: 
  • After appropriate testing, immediately apply patches or appropriate mitigations provided by Microsoft to vulnerable systems.

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

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

  • Inform and educate users regarding 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.