CVE-2012-1876 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 6 through 9, and 10 Consumer Preview, does not properly handle objects in memory, which allows remote attackers to execute arbitrary code by attempting to access a nonexistent object, leading to a heap-based buffer overflow, aka "Col Element Remote Code Execution Vulnerability," as demonstrated by VUPEN during a Pwn2Own competition at CanSecWest 2012.
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Analysis
by VulDB Data Team • 09/01/2025
The vulnerability identified as CVE-2012-1876 represents a critical heap-based buffer overflow flaw in Microsoft Internet Explorer versions 6 through 9, as well as version 10 Consumer Preview. This vulnerability specifically manifests when the browser attempts to handle objects in memory, creating a scenario where remote attackers can manipulate memory operations to execute arbitrary code on affected systems. The flaw was particularly significant because it was demonstrated during the prestigious Pwn2Own competition at CanSecWest 2012 by VUPEN researchers, who successfully exploited the vulnerability to achieve remote code execution. This demonstration highlighted the severe security implications of the issue and its potential for widespread exploitation in real-world scenarios.
The technical root cause of this vulnerability stems from improper memory management within Internet Explorer's handling of col element objects. When the browser encounters certain malformed or unexpected HTML content containing col elements, it fails to properly validate memory boundaries during object access operations. This deficiency creates a condition where an attacker can craft malicious web content that triggers a heap-based buffer overflow when the browser attempts to access a nonexistent object. The vulnerability operates at the memory management level, where insufficient bounds checking allows data to be written beyond the allocated buffer space, potentially overwriting adjacent memory locations with attacker-controlled data. This type of vulnerability falls under CWE-121, which categorizes heap-based buffer overflow conditions, and specifically aligns with the ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation typically enables attackers to execute arbitrary commands on compromised systems.
The operational impact of CVE-2012-1876 extends far beyond simple remote code execution, as it represents a sophisticated attack vector that could be leveraged for complete system compromise. Attackers exploiting this vulnerability could gain unauthorized access to affected systems, potentially installing malware, stealing sensitive data, or using the compromised machines as launch points for further attacks within network environments. The vulnerability's exploitation requires minimal user interaction, as simply visiting a malicious webpage could trigger the exploit, making it particularly dangerous for enterprise environments where users may inadvertently encounter compromised content. Organizations running affected versions of Internet Explorer faced significant risk, as the vulnerability could be exploited through various attack vectors including malicious websites, email attachments, or compromised web applications that served malicious content to users. The widespread adoption of Internet Explorer in corporate environments made this vulnerability particularly impactful, as it could potentially affect large numbers of users with a single successful exploit.
Mitigation strategies for CVE-2012-1876 required immediate action from organizations to protect their systems from exploitation. Microsoft released security patches through Windows Update that addressed the memory handling issues in affected Internet Explorer versions, but organizations needed to ensure timely deployment of these updates across their networks. Alternative mitigation approaches included implementing browser security features such as Internet Explorer's Protected Mode, disabling ActiveX controls, and employing web application firewalls to filter malicious content. Network administrators should have considered implementing security measures like sandboxing Internet Explorer sessions, using alternative browsers, or deploying security solutions that could detect and block exploitation attempts. The vulnerability underscored the importance of keeping browser software updated and implementing defense-in-depth strategies, as the exploitation of such memory corruption vulnerabilities often requires multiple layers of protection to prevent successful compromise of systems. Organizations should have also conducted security assessments to identify and remediate other potential vulnerabilities in their browser configurations, as this particular flaw demonstrated the critical need for proper memory management in web browser implementations.