CVE-2011-2001 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 6 through 9 does not properly handle objects in memory, which allows remote attackers to execute arbitrary code via an attempted access to a virtual function table after corruption of this table has occurred, aka "Virtual Function Table Corruption Remote Code Execution Vulnerability."
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Analysis
by VulDB Data Team • 11/23/2021
This vulnerability represents a critical memory corruption flaw in Microsoft Internet Explorer versions 6 through 9 that falls under the CWE-122 category of buffer overflow conditions. The vulnerability stems from improper handling of objects in memory during virtual function table operations, creating a scenario where attackers can manipulate memory structures to execute arbitrary code remotely. The flaw occurs when the virtual function table becomes corrupted during normal operation, allowing malicious actors to craft specific web content that triggers an attempted access to the corrupted table. This type of vulnerability is particularly dangerous because it leverages the fundamental memory management mechanisms of the browser, making it a prime target for exploitation in web-based attacks.
The technical execution of this vulnerability involves exploiting memory corruption patterns that occur when Internet Explorer attempts to access virtual function pointers after the table structure has been modified or corrupted through previous memory operations. Attackers can craft malicious web pages that cause the browser to perform operations on corrupted virtual function tables, leading to code execution at the privilege level of the browser process. This vulnerability aligns with ATT&CK technique T1059.007 for command and script interpreter execution, as successful exploitation allows attackers to execute arbitrary code within the browser environment. The memory corruption aspect places this vulnerability in the broader context of software security flaws that can lead to privilege escalation and system compromise.
The operational impact of this vulnerability is severe as it affects multiple versions of Internet Explorer, creating a wide attack surface across various enterprise environments. Organizations using these older browser versions face significant risk of remote code execution attacks that could lead to complete system compromise, data theft, or lateral movement within networks. The vulnerability's exploitation requires no user interaction beyond visiting a malicious website, making it particularly dangerous in phishing campaigns or drive-by download scenarios. Security professionals must understand that this vulnerability represents a classic heap corruption issue that has been a primary target for cybercriminals due to its reliability and the prevalence of affected browser versions in corporate environments.
Mitigation strategies for this vulnerability include immediate deployment of Microsoft security updates and patches that address the virtual function table corruption issue. Organizations should implement browser hardening measures such as disabling unnecessary browser features, implementing content security policies, and using sandboxing techniques to limit the potential impact of successful exploitation. Network-based protections such as web application firewalls and intrusion detection systems can help detect and block malicious traffic targeting this vulnerability. Additionally, security teams should conduct comprehensive vulnerability assessments to identify all systems running affected Internet Explorer versions and prioritize their remediation. The vulnerability also underscores the importance of maintaining up-to-date software patches and implementing robust security monitoring to detect potential exploitation attempts. Organizations should consider implementing browser migration strategies to move away from legacy Internet Explorer versions that are no longer supported by Microsoft, as these older versions continue to pose significant security risks due to unpatched vulnerabilities like CVE-2011-2001.