CVE-2013-0094 in Internet Explorer
Summary
by MITRE
Use-after-free vulnerability in Microsoft Internet Explorer 6 through 10 allows remote attackers to execute arbitrary code via a crafted web site that triggers access to a deleted object, aka "Internet Explorer removeChild Use After Free Vulnerability."
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Analysis
by VulDB Data Team • 05/06/2021
The CVE-2013-0094 vulnerability represents a critical use-after-free flaw in Microsoft Internet Explorer versions 6 through 10 that enables remote code execution through malicious web content. This vulnerability specifically manifests when the browser processes web pages containing crafted JavaScript or HTML elements that manipulate DOM objects through the removeChild method. The flaw occurs when Internet Explorer attempts to access memory that has already been freed, creating a condition where attackers can potentially execute arbitrary code with the privileges of the logged-in user.
The technical root cause of this vulnerability lies in the improper memory management within Internet Explorer's JavaScript engine, particularly when handling DOM element removal operations. When a web page triggers the removeChild method on an object that has already been deleted from memory, the browser fails to properly validate the object's existence before attempting to access its properties or methods. This memory corruption vulnerability falls under the CWE-416 category of Use After Free conditions, where memory is accessed after it has been freed by the application. The vulnerability is particularly dangerous because it allows attackers to manipulate the memory layout and potentially inject malicious code that executes within the browser's security context.
The operational impact of CVE-2013-0094 is severe and affects a wide range of Internet Explorer versions that were prevalent during the early 2010s. Attackers can exploit this vulnerability by hosting malicious web content that triggers the specific sequence of DOM operations leading to the use-after-free condition. The exploit typically involves creating a crafted web page that first creates and manipulates DOM elements, then removes them in a way that leaves references pointing to freed memory locations. When subsequent operations attempt to access these freed objects, the attacker can control the execution flow and potentially execute malicious code. This vulnerability is classified under the ATT&CK technique T1203 for Exploitation for Client Execution and T1059 for Command and Scripting Interpreter, as it enables attackers to execute code through browser-based attacks. The vulnerability affects users across multiple Windows operating systems including Windows XP, Vista, 7, and 8, making it particularly dangerous given the widespread deployment of these older Internet Explorer versions.
Mitigation strategies for CVE-2013-0094 include immediate deployment of Microsoft security patches and updates, which address the underlying memory management issues in the browser's JavaScript engine. Organizations should implement browser hardening measures such as disabling JavaScript in trusted environments, implementing content security policies, and using enhanced security features like Internet Explorer's Enhanced Protected Mode. Network-based mitigations include implementing web application firewalls that can detect and block malicious web content patterns associated with this vulnerability, as well as deploying sandboxing solutions that isolate browser processes from critical system resources. Additionally, users should be educated about the risks of visiting untrusted websites and the importance of keeping their browsers updated. The vulnerability also highlights the importance of proper memory management practices in web browser development and serves as a reminder of the critical need for regular security updates and patch management processes. Organizations should also consider migrating to more modern browser technologies that have better memory safety mechanisms and more robust security features compared to the older Internet Explorer versions affected by this vulnerability.