CVE-2009-0075 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 7 does not properly handle errors during attempted access to deleted objects, which allows remote attackers to execute arbitrary code via a crafted HTML document, related to CFunctionPointer and the appending of document objects, aka "Uninitialized Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 11/24/2024
This vulnerability exists in Microsoft Internet Explorer 7 and represents a critical memory corruption flaw that arises from improper error handling during object access operations. The vulnerability specifically manifests when the browser attempts to access deleted objects during document processing, creating a scenario where uninitialized memory becomes accessible to malicious code execution. The flaw is categorized as an uninitialized memory corruption vulnerability, which falls under the broader class of memory safety issues that have long been identified as primary attack vectors in software security. The vulnerability is particularly dangerous because it leverages the CFunctionPointer mechanism and document object appending operations to create exploitable conditions in the browser's memory management system.
The technical exploitation occurs when Internet Explorer encounters a crafted HTML document that triggers an error condition during the handling of deleted objects. During normal browser operation, when objects are deleted from memory, proper cleanup procedures should occur to prevent further access attempts. However, in this case, the error handling mechanism fails to properly validate object states, allowing attackers to manipulate the browser into accessing uninitialized memory regions. This creates a situation where arbitrary code can be injected and executed with the privileges of the user running the browser. The vulnerability's impact is amplified by the fact that it can be triggered through web-based attacks without requiring any special user interaction beyond visiting a malicious website.
From an operational perspective, this vulnerability represents a significant risk to enterprise environments where Internet Explorer 7 remains in use, as it allows remote code execution without user interaction. The attack vector is particularly concerning because it can be delivered through standard web browsing activities, making it difficult to defend against through traditional network security measures. Organizations relying on legacy systems that have not been updated to newer browser versions face severe exposure to this vulnerability. The exploitability of this flaw means that attackers can gain full control over affected systems, potentially leading to data breaches, privilege escalation, and persistent backdoor installations. Security professionals should note that this vulnerability aligns with the attack pattern described in the ATT&CK framework under the 'Exploitation for Privilege Escalation' tactic, where memory corruption vulnerabilities are commonly used to achieve system compromise.
Mitigation strategies for this vulnerability require immediate patching of affected systems, as Microsoft released security updates specifically addressing this flaw. Organizations should prioritize updating to Internet Explorer 8 or later versions, which contain the necessary fixes for this memory corruption issue. Network administrators should implement additional protective measures such as browser hardening configurations, restricted browsing environments, and web application firewalls to reduce the attack surface. The vulnerability also highlights the importance of keeping software current and implementing robust patch management processes, as this type of memory corruption vulnerability typically requires immediate remediation to prevent exploitation. Security teams should monitor for indicators of compromise related to this vulnerability and consider implementing intrusion detection systems that can identify attempts to exploit this specific flaw. The underlying issue demonstrates how improper error handling in complex software systems can create dangerous security vulnerabilities that require careful attention to memory management practices and proper validation of object states during application lifecycle operations.