Researchers Bypass Internet Explorer Protected Mode | threatpost

Researchers Bypass Internet Explorer Protected Mode | threatpost.

A new paper from researchers at Verizon Business identifies a method through which an attacker can bypass Internet Explorer Protected Mode and gain elevated privileges once he’s successfully exploited a bug on the system. Protected Mode in Internet Explorer is one of a handful of key security mechanisms that Microsoft has added to Windows in the last few years. It is often described as a sandbox, in that it is designed to prevent exploitation of a vulnerability in the browser from leading to more persistent compromise of the underlying system. Protected Mode was introduced in Windows Vista and Internet Explorer 7, and other software vendors have followed Microsoft’s lead, introducing sandboxes in applications such as Adobe Reader X and Google Chrome.

The key points and recommended actions are well summarized in Verizon’s own blog post, Evaluating Protected Mode in Internet Explorer:

Since it is not an official security boundary, Microsoft does not guarantee that it will issue patches for bypasses within the monthly patch-cycle.

It can be recommended that domain administrators consider following the steps below to improve the security of Protected Mode Internet Explorer in the enterprise:

  • Ensure that User Access Control (UAC) is enabled, as disabling it will also disable Protected Mode.
  • Ensure that workstation users cannot run as administrators.
  • Enable Protected Mode for all zones where possible.
  • Disable the Local Intranet Zone, or limit the members of the zone as far as possible.
  • Ensure that third-party software vendors create software which does not incorrectly configure Internet Explorer’s elevation policy and introduce privilege escalation bugs that allow malicious code to escape from Protected Mode.