CVE-2012-0011 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 7 through 9 does not properly handle objects in memory, which allows remote attackers to execute arbitrary code by accessing a deleted object, aka "HTML Layout Remote Code Execution Vulnerability."
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 03/20/2021
This vulnerability exists in Microsoft Internet Explorer versions 7 through 9 and represents a critical memory corruption flaw that enables remote code execution through improper object handling in memory management. The vulnerability specifically occurs when Internet Explorer fails to properly manage object references in memory, creating situations where deleted objects remain accessible to malicious code. This memory management issue stems from the browser's failure to correctly implement reference counting or garbage collection mechanisms for HTML layout objects, allowing attackers to exploit dangling pointers that point to freed memory regions. The flaw falls under CWE-466, which categorizes improper handling of pointers to freed memory, making it a classic example of memory safety vulnerability that has plagued web browsers for years.
The technical exploitation of this vulnerability involves crafting malicious HTML content that triggers specific memory operations within Internet Explorer's rendering engine. Attackers can create HTML layouts that cause the browser to delete objects while maintaining references to them, then manipulate the memory to execute arbitrary code when these deleted objects are accessed. This technique leverages the browser's layout engine's memory management deficiencies, particularly in how it handles complex HTML structures and CSS properties that interact with JavaScript objects. The vulnerability is particularly dangerous because it can be triggered through standard web browsing activities, making it an ideal candidate for drive-by download attacks that exploit the user's browser without requiring any special privileges or user interaction beyond visiting a compromised website.
The operational impact of CVE-2012-0011 is severe and far-reaching, affecting millions of users who relied on Internet Explorer 7 through 9 for daily web browsing activities. Organizations running legacy systems with these browser versions faced significant risk exposure, as the vulnerability could be exploited through various attack vectors including malicious websites, email attachments, or compromised web services. The remote code execution capability means that attackers could gain complete control over affected systems, potentially leading to data breaches, system compromise, and lateral movement within network environments. This vulnerability particularly affected enterprise environments where older browser versions were still in use due to compatibility requirements with legacy applications, creating widespread exposure across both consumer and corporate networks.
Mitigation strategies for this vulnerability required immediate patch deployment through Microsoft's security updates, specifically addressing the memory management flaws in Internet Explorer's object handling mechanisms. Organizations should have implemented browser lockdown policies, restricted internet access for critical systems, and deployed intrusion detection systems to monitor for exploitation attempts. The remediation process involved updating to patched versions of Internet Explorer, with many organizations implementing browser virtualization or sandboxing solutions as additional protective measures. This vulnerability highlighted the importance of maintaining up-to-date security patches and demonstrated how memory safety issues in web browsers could be exploited to achieve complete system compromise. Security professionals should have monitored exploit kits and malicious websites that leveraged this vulnerability, while also implementing network segmentation to limit the potential impact of successful exploitation attempts. The incident reinforced the need for comprehensive browser security management and the importance of transitioning away from unsupported browser versions that continue to pose significant security risks to organizations.