CVE-2007-3481 in Internet Explorer
Summary
by MITRE
** DISPUTED ** Cross-domain vulnerability in Microsoft Internet Explorer 6 and 7 allows remote attackers to bypass the Same Origin Policy and access restricted information from other domains via JavaScript that overwrites the document variable and statically sets the document.domain attribute. NOTE: this issue has been disputed by other researchers, citing a variable scoping issue and information about the semantics of document.domain.
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Analysis
by VulDB Data Team • 08/08/2024
The vulnerability described in CVE-2007-3481 represents a significant cross-domain security flaw in Microsoft Internet Explorer versions 6 and 7 that potentially undermines fundamental web security principles. This issue operates through a sophisticated manipulation of JavaScript execution contexts and document object handling within the browser's rendering engine, creating a pathway for attackers to circumvent the critical Same Origin Policy that forms the cornerstone of web security architecture. The vulnerability's disputed nature stems from the complex interplay between JavaScript variable scoping rules and the document.domain attribute manipulation, which researchers have debated extensively regarding the actual exploitability and underlying mechanisms.
The technical exploitation mechanism involves attackers crafting malicious JavaScript code that specifically targets the document variable within Internet Explorer's JavaScript engine. By overwriting the document variable and statically setting the document.domain attribute, attackers can manipulate the browser's domain security boundaries to access resources that should normally be restricted to the originating domain. This technique exploits a fundamental weakness in how Internet Explorer handles cross-domain security contexts, particularly when JavaScript code attempts to modify domain-related properties that should remain immutable. The vulnerability leverages the browser's handling of document.domain assignment to artificially extend the security boundary, allowing access to objects and data from different domains that would normally be protected by the same origin policy.
From an operational perspective, this vulnerability presents a severe risk to web application security and user data protection, particularly in environments where Internet Explorer 6 and 7 were still in use. The impact extends beyond simple information disclosure to potentially enable more sophisticated attacks including session hijacking, data exfiltration, and cross-site scripting exploitation. Security researchers have noted that the vulnerability's effectiveness depends heavily on the specific conditions under which the malicious JavaScript executes, including the presence of certain DOM elements and the browser's current security context. The disputed nature of this vulnerability according to other researchers suggests that the actual exploitability may be more limited than initially reported, with some experts arguing that the variable scoping issues and document.domain semantics make the attack vector less straightforward than described.
The security implications of this vulnerability align with CWE-284, which addresses improper access control mechanisms, and relate to the broader category of cross-domain scripting attacks that have been extensively documented in security literature. This issue demonstrates the complexity of web browser security implementations and highlights how seemingly minor implementation details in JavaScript handling can create significant security holes. Organizations using these older Internet Explorer versions faced particular risk as the vulnerability could be exploited through social engineering campaigns, drive-by downloads, or by compromising websites that hosted malicious content. The ATT&CK framework categorizes this type of vulnerability under privilege escalation and defense evasion techniques, as it allows attackers to bypass security boundaries that should normally prevent cross-domain access. Mitigation strategies typically involve updating to newer browser versions, implementing proper content security policies, and using additional security headers to limit the potential impact of such vulnerabilities. However, the disputed nature of the vulnerability suggests that organizations should carefully evaluate the actual risk based on their specific deployment environments and browser usage patterns, as the exploitation requirements may be more restrictive than initially indicated by some security reports.