Microsoft Internet Explorer Use-After-Free Remote Code Execution Vulnerability (CVE-2010-0249, Operation Aurora)

1. Apply Official Security Patch

Apply the Microsoft cumulative security update KB979352 or later to resolve this memory corruption vulnerability.

2. Temporary Workarounds (For Legacy Environments)

• Enable Data Execution Prevention (DEP):

Force system-wide DEP to prevent the execution of shellcode from memory pages designated as non-executable.

  bcdedit /set {current} nx AlwaysOn

• Disable Active Scripting:

Configure Internet Explorer security zone settings for 'Internet' and 'Local Intranet' to 'High' to prompt or disable Active Scripting, preventing automated exploitation via JavaScript.

• Deploy Exploit Mitigations:

Utilize security mitigation toolkits (such as EMET on legacy systems) to block common heap exploitation techniques.

This vulnerability is a highly critical flaw historically exploited as a zero-day in the wild during the infamous 'Operation Aurora' APT campaigns.

Root Cause & Exploit Mechanics (CWE-416)

The vulnerability exists within the HTML rendering engine of Internet Explorer and how it manages DOM objects in memory.

• Object Deallocation: A DOM object is deleted from memory during specific event handling or script execution.
• Dangling Pointer: The pointer referencing the deleted object is not properly cleared (set to NULL), leaving a dangling pointer in memory.
• Heap Manipulation: An attacker uses JavaScript to perform heap spraying, filling the freed memory space with controlled malicious data.
• Use-After-Free Execution: When the browser attempts to access the deleted object via the dangling pointer, it executes the attacker-controlled data, leading to arbitrary shellcode execution.