CVE-2004-1104 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 6.0 SP2 allows remote attackers to spoof a legitimate URL in the status bar and conduct a phishing attack via a web page that contains a BASE element that points to the legitimate site, followed by an anchor (a) element with an empty "href" attribute, and a FORM whose action points to a malicious URL, and an INPUT submit element that is modified to look like a legitimate URL.
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Analysis
by VulDB Data Team • 09/17/2025
This vulnerability represents a sophisticated cross-site scripting and phishing attack vector that exploits the trust relationship between web browsers and users. The flaw exists in Microsoft Internet Explorer 6.0 Service Pack 2 and demonstrates how seemingly innocuous HTML elements can be orchestrated to create deceptive user experiences. The vulnerability leverages the browser's handling of the BASE element which establishes a base URL for relative references within a document, combined with the status bar display behavior that typically shows the URL of the current page or the target of a link. When a malicious web page incorporates this specific sequence of HTML elements, it manipulates the browser's status bar to display a legitimate URL while simultaneously preparing a form submission that redirects to an attacker-controlled destination.
The technical exploitation mechanism relies on the interaction between multiple HTML elements to create a deceptive environment. The BASE element establishes a legitimate domain context, while the anchor element with an empty href attribute creates a visual cue that appears to point to the base URL. The FORM element with a malicious action attribute and INPUT submit element that mimics legitimate URL presentation work together to create a scenario where users see a trusted URL in the status bar but are actually being directed to a malicious destination. This technique specifically targets user trust in browser status bar displays and the assumption that URLs shown in the status bar represent the actual destination of web interactions.
The operational impact of this vulnerability extends beyond simple phishing attacks to encompass broader security implications for web-based authentication and trust mechanisms. Users who rely on status bar URL verification for security decisions may be deceived into believing they are interacting with legitimate services when they are actually communicating with malicious actors. The attack requires no special privileges or complex exploitation techniques, making it particularly dangerous as it can be executed through standard web browsing activities. Security researchers have classified this as a variant of credential harvesting attacks that exploit user psychology and browser trust models rather than technical protocol flaws, aligning with ATT&CK technique T1566 for credential access through phishing.
The vulnerability demonstrates a fundamental weakness in browser security model assumptions, particularly regarding user interface elements that are expected to provide security assurance. It highlights how HTML-based deception techniques can bypass traditional security controls by exploiting the gap between technical implementation and user expectations. The attack vector specifically targets the status bar display mechanism, which is considered a trusted security indicator by users and security professionals alike. This vulnerability represents a classic example of how user interface security can be subverted through careful manipulation of HTML parsing and display behavior, with implications for web security practices and user education.
Mitigation strategies for this vulnerability require both browser-level fixes and user awareness measures. Microsoft addressed this issue through browser updates that modified how status bar displays are handled and how URL references are resolved in the presence of BASE elements. Organizations should implement comprehensive web filtering and security awareness training to help users recognize and avoid suspicious web interactions. The vulnerability also underscores the importance of maintaining current browser versions and security patches, as it represents an attack that could have been prevented through proper security maintenance. Security professionals should consider this vulnerability when implementing web security policies and user training programs, particularly focusing on the trust relationship between users and browser interface elements.