Security Update for Internet Explorer (MS15-106) (UPDATED)

ITS Advisory Number: 
2015-123
Date(s) Issued: 
Tuesday, October 13, 2015
Date Updated: 
Friday, October 30, 2015
Subject: 
Security Update for Internet Explorer (MS15-106) (UPDATED)
Overview: 

ORIGINAL OVERVIEW:

This security update resolves vulnerabilities in Internet Explorer. The most severe of the vulnerabilities could allow remote code execution if a user views a specially crafted webpage using Internet Explorer. An attacker who successfully exploited these vulnerabilities could gain the same user rights as the current user. Customers whose accounts are configured to have fewer user rights on the system could be less impacted than those who operate with administrative user rights.

October 30 UPDATED OVERVIEW:

One memory corruption vulnerability (CVE-2015-6056) has been publicly disclosed. This additional vulnerability could allow for remote code execution.

 

Systems Affected: 
  • Internet Explorer 11
  • Internet Explorer 10
  • Internet Explorer 9
  • Internet Explorer 8
  • Internet Explorer 7
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: 
High
Description: 

ORIGINAL DESCRIPTION:

The security update addresses the vulnerabilities by:

  • Modifying how Internet Explorer handles objects in memory [CVE-2015-6042], [CVE-2015-6048], [CVE-2015-6049], [CVE-2015-6050]
  • Modifying how Internet Explorer, JScript, and VBScript handle objects in memory [CVE-2015-2482], [CVE-2015-6055], [CVE-2015-6056]
  • When Internet Explorer does not properly validate permissions under specific conditions, potentially allowing a script to be run with elevated privileges. [CVE-2015-6044], [CVE-2015-6047], [CVE-2015-6051]
  • When Internet Explorer improperly discloses the contents of its memory. [CVE-2015-6046], [CVE-2015-6053]

Workarounds have been noted and should be referenced at https://technet.microsoft.com/library/security/MS15-106

These vulnerabilities could allow remote code execution or an elevation of privilege if a user views a specially crafted webpage in Internet Explorer. An attacker who successfully exploits this vulnerability could gain the same user rights as the current user. Depending on the privileges associated with the user, an attacker could install programs; view, change, or delete data; or create new accounts with full user rights.

OCTOBER 30 UPDATED DESCRIPTION:

Internet Explorer 11 is vulnerable to a memory corruption vulnerability that could allow for remote code execution.  This vulnerability only affects Internet Explorer installations on Windows 10. (CVE-2015-6045)

Actions: 
  • After appropriate testing, apply appropriate patches provided by Microsoft to vulnerable systems.
  • 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 follow links provided by unknown or untrusted sources.
  • Do not open email attachments from unknown or untrusted sources or suspicious emails from trusted sources.