CVE-2012-4792 in Internet Explorer
Summary
by MITRE
Use-after-free vulnerability in Microsoft Internet Explorer 6 through 8 allows remote attackers to execute arbitrary code via a crafted web site that triggers access to an object that (1) was not properly allocated or (2) is deleted, as demonstrated by a CDwnBindInfo object, and exploited in the wild in December 2012.
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Analysis
by VulDB Data Team • 04/22/2026
This vulnerability represents a critical use-after-free flaw in Microsoft Internet Explorer versions 6 through 8 that enables remote code execution through malicious web content. The issue stems from improper memory management where an object remains accessible in memory even after it has been freed, creating a window of opportunity for attackers to manipulate the freed memory location. The specific exploitation involves the CDwnBindInfo object which demonstrates how the browser fails to properly validate object states during the cleanup process, allowing attackers to control memory contents and redirect execution flow.
The technical implementation of this vulnerability leverages the fundamental principle of memory corruption where freed memory blocks are not properly invalidated or reallocated, creating a scenario where subsequent memory operations can overwrite the freed object with attacker-controlled data. This particular flaw operates within the context of Internet Explorer's download handling mechanism, where the CDwnBindInfo object maintains state information during download operations. When the object is prematurely freed while still being referenced or accessed by other components, attackers can craft malicious web content that triggers the use of this freed memory location, effectively creating a memory corruption condition.
From an operational perspective, this vulnerability has significant implications for enterprise security environments where legacy Internet Explorer versions remain in use. The exploitation occurred in the wild during December 2012, indicating real-world threat actor interest and active exploitation of the flaw. The attack vector requires remote code execution through web-based delivery, making it particularly dangerous for organizations that do not maintain up-to-date browser security patches. The vulnerability's impact extends beyond individual user sessions to potentially compromise entire corporate networks, especially when legacy systems continue to operate without proper security controls.
The mitigation strategies for this vulnerability primarily focus on immediate patching and browser upgrades to versions that address the memory management flaw. Microsoft released security updates that corrected the improper object deallocation and memory cleanup processes within Internet Explorer. Organizations should implement comprehensive patch management procedures and consider browser virtualization or sandboxing techniques to reduce the attack surface. Additionally, network security controls such as web application firewalls and content filtering can provide additional layers of protection against exploitation attempts. This vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions, and represents a classic example of how improper memory management can lead to remote code execution in web browsers. The ATT&CK framework categorizes this under T1203, which involves exploitation of remote services, and T1059, covering command and scripting interpreters, as attackers leverage the compromised browser to execute malicious payloads. Organizations must ensure that legacy browser support is carefully managed and eventually phased out in favor of modern secure browser implementations that have robust memory safety mechanisms and regular security updates.