A Vulnerability in Microsoft Internet Explorer Could Allow for Arbitrary Code Execution

ITS ADVISORY NUMBER: 
2020-010

DATE(S) ISSUED: 
Tuesday, January 21, 2020

SUBJECT: 
A Vulnerability in Microsoft Internet Explorer Could Allow for Arbitrary Code Execution

OVERVIEW: 
A vulnerability has been discovered in Microsoft Internet Explorer, which could allow for arbitrary code execution. Microsoft Internet Explorer is a web browser available for Microsoft Windows. Successful exploitation of this vulnerability could allow for arbitrary code execution. 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 reports of limited CVE-2020-0674 exploitation in the wild.

SYSTEMS AFFECTED: 

  • Internet Explorer 9 for Windows Server 2008
  • Internet Explorer 10 for Windows Server 2012
  • Internet Explorer 11 for Windows 7, 8.1, RT 8.1, 10
  • Internet Explorer 11 for Windows Server 2008, 2008 R2, 2012, 2012 R2, 2016, 2019

RISK:

Government:
Large and medium government entities: High
Small government entities: High

Business:
Large and medium business entities: High
Small business entities: High

Home Users: Medium

DESCRIPTION: 
A vulnerability has been discovered in Microsoft Internet Explorer, which could allow for arbitrary code execution. The vulnerability occurs due to a memory corruption issue in the Internet Explorer Scripting Engine. In a web-based attack scenario, an attacker could convince a user to view a specially crafted website via Internet Explorer. The workaround addresses the vulnerability by modifying how the scripting engine handles objects in memory.  Successful exploitation of this vulnerability could allow for arbitrary code execution. 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.

REFERENCES: 

Microsoft:
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/ADV20...

CVE:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-0674