CVE-2012-0169 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 9 does not properly handle objects in memory, which allows remote attackers to execute arbitrary code by accessing a deleted object, aka "JScript9 Remote Code Execution Vulnerability."
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Analysis
by VulDB Data Team • 03/22/2021
The CVE-2012-0169 vulnerability represents a critical memory corruption flaw in Microsoft Internet Explorer 9 that stems from improper handling of objects in memory during the JavaScript execution process. This vulnerability specifically affects the JScript9 engine component that powers script execution in IE9, creating a condition where attackers can manipulate memory references to access deleted objects through carefully crafted malicious web content. The flaw occurs when the browser's memory management system fails to properly track object lifecycles, leading to situations where freed memory locations can be accessed and manipulated by malicious scripts. This type of vulnerability falls under the category of use-after-free conditions, which are particularly dangerous because they allow attackers to execute arbitrary code with the privileges of the victim user.
The technical exploitation of this vulnerability leverages the fundamental memory management mechanisms within Internet Explorer's JavaScript engine, where objects are allocated and deallocated from memory without proper synchronization or validation checks. When a script attempts to access an object that has already been freed from memory, the system may return a pointer to that memory location, which can then be manipulated by an attacker to overwrite critical memory structures or inject malicious code. This vulnerability specifically impacts the JScript9 runtime environment and demonstrates weaknesses in the browser's object lifecycle management, where deleted objects remain accessible through dangling pointers or improper reference counting mechanisms. The vulnerability is classified as a use-after-free condition under CWE-416, which directly maps to the memory corruption patterns that enable remote code execution in modern browsers.
The operational impact of CVE-2012-0169 extends beyond simple exploitation as it represents a significant threat to enterprise security environments where Internet Explorer remains in use. Attackers can leverage this vulnerability through phishing campaigns, malicious websites, or compromised advertising networks to deliver payloads that execute arbitrary code on targeted systems. The vulnerability is particularly dangerous because it operates at the browser level, allowing attackers to bypass many traditional security controls and potentially escalate privileges to system level access. This flaw can be exploited through various attack vectors including malicious web pages, email attachments, or compromised websites that deliver malicious JavaScript payloads designed to trigger the memory corruption condition. Organizations running IE9 without proper patching are at high risk of compromise, as this vulnerability has been widely documented in exploitation frameworks and represents a common target for advanced persistent threats.
Mitigation strategies for CVE-2012-0169 primarily focus on immediate patch deployment and browser security hardening measures. Microsoft released a security update that addressed the memory management issues in the JScript9 engine by implementing proper object lifecycle tracking and memory validation checks. Organizations should prioritize patch management processes to ensure all IE9 installations receive the applicable security update. Additional protective measures include implementing browser security features such as enhanced protection modes, disabling unnecessary browser components, and deploying application whitelisting solutions. The vulnerability demonstrates the importance of memory safety in modern browser architectures and aligns with ATT&CK technique T1059.007 for Windows Command Shell execution, as attackers can leverage this vulnerability to establish persistent access through malicious code execution. Network security controls including web application firewalls and content filtering systems can provide additional layers of protection, though the most effective defense remains timely patch deployment and browser security configuration management.