MS-ISAC CYBERSECURITY ADVISORIES
MS-ISAC ADVISORY NUMBER:
Multiple Vulnerabilities in Microsoft Office Could Allow for Remote Code Execution (MS16-088)
There are currently no reports of these vulnerabilities being exploited in the wild.
SYSTEMS AFFECTED INTELLIGENCE:
- Microsoft Office Compatibility Pack Service Pack 3
- Microsoft Excel Viewer
- Microsoft Word Viewer
- Microsoft SharePoint Server 2010, 2013, 2016
- Microsoft Office Web Apps 2010, 2013
- Microsoft Office Online Server
- Large and medium government entities: High
- Small government entities: Medium
- Large and medium business entities: High
- Small business entities: Medium
Home users: Low
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.
- Six memory corruption vulnerabilities exist when the Office software fails to properly handle objects in memory. (CVE-2016-3278, CVE-2016-3280, CVE-2016-3281, CVE-2016-3282, CVE-2016-3283, CVE-2016-3284)
- A remote code execution vulnerability exists when Office fails to properly handle XLA files. (CVE-2016-3279)
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.
We recommend the following actions be taken:
- We recommend the following actions be taken:
- Apply appropriate patches provided by Microsoft 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
- Apply the principle of Least Privilege to all systems and services.Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from un-trusted sources
- Inform and educate users regarding the threats posed by hypertext links contained in emails or attachments especially from untrusted sources.