Microsoft Office for Mac Vulnerability Identified

Microsoft Office for Mac Vulnerability Identified

A cybersecurity alert was issued Monday, Nov. 4, 2019, regarding a vulnerability in Microsoft Office for Mac. The vulnerability could allow an attacker to execute code which could potentially lead to a breach.

What It Is:
A vulnerability has been discovered in Microsoft Office for Mac which could allow for remote code execution. Microsoft Office for Mac is an office productivity software.

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.

Read the original CMU – Software Engineering Institute Vulnerability Note.

Threat Intelligence:
There is currently no report of this vulnerability being exploited in the wild.

Systems Affected:

• Microsoft Office 2011 for Mac

• Large and medium government entities: High
• Small government entities: Medium
• Large and medium business entities: High
• Small business entities: Medium
Home users: Low

What It Means:
If you and/or your business utilize the vBulletin versions mentioned above, you will need to apply appropriate updates provided by vBulletin to vulnerable systems following proper testing.

Technical Summary:
A vulnerability has been discovered in Microsoft Office for Mac, which could allow for remote code execution. In an email attack scenario, an attacker could exploit these vulnerabilities by sending a specially crafted file to a 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 this vulnerability. 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.

What To Do:
We recommend the following actions be taken:

• Block SYLK files over web and email gateways.
• Block SYLK files in Microsoft Office 2011 for Mac.
• Enable the security setting "Disable all macros with notification."
• Since Microsoft Office 2011 for Mac is end of life, update to a supported version immediately after appropriate testing because no patch is available for the 2011 version.
• 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 untrusted websites or open attachments 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.

Negative Consequences of Lost or Stolen Data:
The loss or theft of proprietary data can have severe impacts, particularly if the compromise becomes public and sensitive information is exposed. Possible impacts include:

• Temporary or permanent loss of sensitive or proprietary information.
• Disruption to regular operations.
• Financial losses incurred to restore systems and files.
• Potential harm to an organization’s reputation.

Should your agency or business need assistance with issues arising from vulnerabilities in Microsoft Office for Mac including updates and/or patches, Dox can help. Please contact Dox if there is anything we can do to assist in securing your agency, business, or organization.

Thank you for your time and stay safe online.