CVE-2009-1140 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 5.01 SP4; 6 SP1; 6 and 7 for Windows XP SP2 and SP3; 6 and 7 for Server 2003 SP2; 7 for Vista Gold, SP1, and SP2; and 7 for Server 2008 SP2 does not prevent HTML rendering of cached content, which allows remote attackers to bypass the Same Origin Policy via unspecified vectors, aka "Cross-Domain Information Disclosure Vulnerability."
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Analysis
by VulDB Data Team • 11/13/2025
This vulnerability represents a critical cross-domain information disclosure issue in Microsoft Internet Explorer versions spanning multiple releases from IE 5.01 through IE 7. The flaw specifically relates to how the browser handles cached HTML content and fails to properly enforce the Same Origin Policy that governs web security boundaries. The vulnerability exists in the browser's caching mechanism where it does not adequately prevent rendering of cached content from different origins, creating a pathway for malicious actors to access sensitive information across domain boundaries. This represents a fundamental breakdown in browser security architecture that violates core web security principles.
The technical implementation of this vulnerability stems from IE's insufficient validation of cached content during HTML rendering processes. When Internet Explorer caches web content, it does not properly isolate cached resources from different domains, allowing cached HTML elements to be rendered even when they originate from different security contexts. This behavior creates an attack surface where remote adversaries can exploit the caching mechanism to bypass security restrictions that should prevent cross-domain data access. The vulnerability operates through unspecified vectors that typically involve crafting malicious web pages or leveraging existing cached content to extract information that should remain isolated between different origins.
The operational impact of this vulnerability is significant as it enables remote attackers to perform cross-domain information disclosure attacks that could lead to unauthorized data access. Attackers can potentially extract sensitive information from cached resources, including session cookies, user data, or other confidential content that should be protected by the Same Origin Policy. This vulnerability particularly affects users of older IE versions on various Windows platforms, making it a persistent threat in environments where legacy browser support is maintained. The risk is compounded by the fact that cached content often contains sensitive information that users may not expect to be accessible across different domains.
Mitigation strategies for this vulnerability require a multi-layered approach focusing on both browser updates and network-level protections. Organizations should prioritize immediate deployment of Microsoft security updates and patches that address this specific caching behavior. Browser configuration changes can include disabling caching for sensitive content or implementing stricter security policies within the browser environment. Network administrators should consider implementing content filtering solutions that can detect and block potentially malicious content that exploits this vulnerability. Additionally, user education regarding safe browsing practices and the risks associated with legacy browser usage remains crucial. This vulnerability aligns with CWE-200 (Information Exposure) and represents a violation of ATT&CK technique T1566 (Phishing) and T1071.1001 (Application Layer Protocol: Web Protocols) where adversaries leverage browser security flaws to gain unauthorized access to information.