CVE-2002-0188 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 5.01 and 6.0 allow remote attackers to execute arbitrary code via malformed Content-Disposition and Content-Type header fields that cause the application for the spoofed file type to pass the file back to the operating system for handling rather than raise an error message, aka the second variant of the "Content Disposition" vulnerability.
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Analysis
by VulDB Data Team • 04/07/2017
The vulnerability identified as CVE-2002-0188 represents a critical security flaw in Microsoft Internet Explorer versions 5.01 and 6.0 that enables remote code execution through improper handling of HTTP header fields. This vulnerability specifically targets the Content-Disposition and Content-Type header parsing mechanisms within the browser's security architecture. The flaw operates by exploiting how Internet Explorer processes these headers when downloading files from web servers, creating a pathway for attackers to execute malicious code on vulnerable systems. The vulnerability is categorized under CWE-121 as a buffer overflow condition, though the specific mechanism involves improper input validation rather than traditional buffer manipulation.
The technical implementation of this vulnerability occurs when Internet Explorer encounters malformed Content-Disposition and Content-Type headers in HTTP responses from web servers. These headers typically instruct the browser how to handle downloaded content, with Content-Disposition specifying whether content should be displayed inline or saved as a file, and Content-Type indicating the MIME type of the content. When these headers contain malformed data that triggers unexpected behavior in the browser's parsing logic, the application fails to properly validate the file type information. This validation failure causes the browser to incorrectly determine the file type and subsequently pass the malicious file back to the operating system for automatic handling without proper security checks.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass a broader attack surface that leverages user trust and browser automation. Attackers can craft malicious web pages that serve content with specially crafted headers designed to bypass the browser's security mechanisms. When users browse to these malicious sites, the browser's automatic file handling process triggers, potentially executing malicious code without user interaction or awareness. The vulnerability is particularly dangerous because it exploits the trust relationship between the browser and the operating system, allowing attackers to bypass typical security boundaries that would normally prevent automatic execution of downloaded content. This attack vector aligns with ATT&CK technique T1203 for Exploitation for Client Execution, where adversaries leverage vulnerabilities in applications to execute malicious code.
The security implications of CVE-2002-0188 are significant given that Internet Explorer was widely deployed in enterprise environments and personal computing scenarios during this period. The vulnerability's exploitation requires minimal user interaction beyond visiting a malicious website, making it particularly effective for phishing campaigns and drive-by download attacks. The flaw demonstrates a fundamental issue in how the browser handles file type detection and validation, creating a persistent security risk that could be exploited across multiple operating system versions. Organizations using these vulnerable browser versions faced substantial risk of compromise, as the vulnerability could be exploited through various attack vectors including malicious websites, email attachments, and compromised web servers. The vulnerability's classification as a second variant of the Content Disposition vulnerability indicates that it was part of a broader class of issues affecting web browser security implementations. Mitigation strategies for this vulnerability typically included applying Microsoft security patches, disabling automatic file execution features, and implementing network-level controls to filter suspicious HTTP headers. The incident highlighted the importance of proper input validation in web browsers and the need for comprehensive security testing of HTTP header processing mechanisms.