CVE-2002-0980 in Outlook
Summary
by MITRE
The Web Folder component for Internet Explorer 5.5 and 6.0 writes an error message to a known location in the temporary folder, which allows remote attackers to execute arbitrary code by injecting it into the error message, then referring to the error message file via a mhtml: URL.
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Analysis
by VulDB Data Team • 06/23/2025
The vulnerability described in CVE-2002-0980 represents a critical security flaw in the Web Folder component of Internet Explorer versions 5.5 and 6.0 that exploits a path traversal and code execution vector through temporary file manipulation. This vulnerability operates by leveraging the way Internet Explorer handles error messages within its Web Folder component, which creates temporary files in predictable locations within the system's temporary directory structure. The flaw specifically targets the insecure handling of error messages where the application writes diagnostic information to a known temporary file path, creating a potential attack surface for remote code execution.
The technical implementation of this vulnerability involves the exploitation of a predictable file location within the temporary folder where error messages are stored. When Internet Explorer encounters certain malformed web content or encounters issues with web folder operations, it generates error messages that are written to a specific location in the temporary directory. Attackers can manipulate this process by injecting malicious code into the error message through crafted web content that triggers the error condition. The injected code becomes persistent in the temporary file, creating a remote execution vector when the malicious file is subsequently accessed through a mhtml: URL reference.
The operational impact of this vulnerability extends beyond simple code execution to encompass a complete compromise of the affected system's security posture. The attack requires no user interaction beyond visiting a malicious website or opening a specially crafted web page, making it particularly dangerous for widespread exploitation. The mhtml: URL protocol allows attackers to reference local files on the victim's system, including the malicious error message file, enabling the execution of arbitrary code with the privileges of the user running Internet Explorer. This vulnerability directly relates to CWE-22 Path Traversal and CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component, which are fundamental weaknesses in input validation and output handling.
The exploitation of this vulnerability follows patterns consistent with the ATT&CK framework's execution techniques, particularly those involving the use of malicious files and web-based attack vectors. The attack chain begins with initial access through a malicious website, followed by the injection of malicious code into the temporary file through error message handling, and concludes with code execution through the mhtml: URL protocol. This vulnerability demonstrates the dangerous intersection of temporary file handling, web protocol implementation, and privilege escalation in web browser environments, making it a prime example of how seemingly innocuous error handling can create critical security risks.
Mitigation strategies for this vulnerability require multiple layers of defensive measures including immediate patching of affected Internet Explorer versions, implementation of proper temporary file access controls, and network-level restrictions on mhtml: URL protocols. System administrators should disable unnecessary web folder functionality, implement strict temporary file permissions, and deploy network monitoring to detect suspicious mhtml: URL access patterns. The vulnerability highlights the importance of secure coding practices around temporary file handling and demonstrates why applications should avoid writing sensitive information to predictable file locations. Organizations should also consider implementing browser hardening measures and regular security assessments to identify similar vulnerabilities in other components of their web infrastructure.