CVE-2007-1751 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 5.01, 6, and 7 allows remote attackers to execute arbitrary code by causing Internet Explorer to access an uninitialized or deleted object, related to prototype variables and table cells, aka "Uninitialized Memory Corruption Vulnerability."
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Analysis
by VulDB Data Team • 04/07/2017
This vulnerability represents a critical memory corruption flaw in Microsoft Internet Explorer versions 5.01, 6, and 7 that enables remote code execution through improper handling of prototype variables and table cells. The issue stems from Internet Explorer's failure to properly initialize memory objects when processing web content, creating opportunities for attackers to manipulate memory structures and execute malicious code. The vulnerability specifically affects how the browser handles prototype variables within table cell elements, leading to scenarios where memory locations may be accessed without proper initialization or validation.
The technical exploitation occurs when Internet Explorer encounters web content that triggers the use of uninitialized memory objects during the rendering process. This memory corruption vulnerability allows attackers to manipulate the browser's memory management system by crafting malicious web pages that force the browser to access memory locations containing stale or improperly initialized data. The flaw operates at the intersection of JavaScript object model handling and HTML table processing, where prototype variables associated with table cells are not properly validated before use. This represents a classic case of uninitialized memory access that falls under the CWE-457 category of "Use of Uninitialized Variable" and can be categorized as a memory corruption vulnerability under CWE-125.
From an operational impact perspective, this vulnerability poses significant risks to enterprise environments where Internet Explorer remains in use, particularly in legacy systems or organizations that have not fully migrated to modern browser technologies. Attackers can leverage this vulnerability to execute arbitrary code with the privileges of the logged-in user, potentially leading to complete system compromise, data exfiltration, or establishment of persistent backdoors. The vulnerability's remote exploitation capability means that users can be compromised simply by visiting malicious websites or opening specially crafted email attachments containing web content. This aligns with ATT&CK technique T1203 for "Exploitation for Client Execution" and demonstrates how memory corruption vulnerabilities can be weaponized for lateral movement and privilege escalation within network environments.
The recommended mitigations for this vulnerability include immediate deployment of Microsoft security patches and updates, which address the underlying memory management issues in the browser's object handling mechanisms. Organizations should also implement browser hardening measures such as disabling unnecessary browser features, implementing content security policies, and deploying web application firewalls to filter malicious content. Additionally, user education regarding safe browsing practices and awareness of social engineering tactics that might exploit this vulnerability remains crucial. For environments where patching is not immediately possible, network segmentation and monitoring for suspicious web traffic can provide additional layers of defense against exploitation attempts. The vulnerability highlights the importance of proper memory management in browser implementations and the critical need for regular security updates to address known memory corruption issues.