CVE-2002-2100 in Outlook
Summary
by MITRE
Microsoft Outlook 2002 allows remote attackers to embed bypass the file download restrictions for attachments via an HTML email message that uses an IFRAME to reference malicious content.
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Analysis
by VulDB Data Team • 07/08/2024
This vulnerability in Microsoft Outlook 2002 represents a significant security flaw that exploits the email client's handling of HTML content and attachment restrictions. The vulnerability specifically targets the way Outlook processes iframe elements within HTML email messages, allowing attackers to circumvent built-in security mechanisms designed to prevent automatic downloading of potentially malicious attachments. The flaw resides in the client-side rendering engine that fails to properly validate or restrict the loading of external content referenced through iframe tags, creating an attack vector that bypasses the intended security controls.
The technical implementation of this vulnerability leverages the HTML iframe element to reference malicious content hosted on external servers. When Outlook processes an HTML email containing an iframe tag, it attempts to load the referenced content, which can include malicious scripts, executables, or other harmful payloads. This behavior occurs despite the presence of file download restrictions that should prevent automatic execution or downloading of attachments. The vulnerability is particularly dangerous because it operates within the legitimate email processing flow, making it difficult for users to distinguish between safe and malicious content based on visual indicators alone.
The operational impact of this vulnerability extends beyond simple content display issues, as it fundamentally undermines the security model that Outlook employs to protect users from potentially harmful attachments. Attackers can craft emails that appear benign while simultaneously loading malicious content from external sources, effectively bypassing the email client's security restrictions. This creates a scenario where users may be unaware that malicious content is being loaded and executed, potentially leading to system compromise, data theft, or further attack escalation. The vulnerability affects the core email processing functionality and represents a failure in the security boundary enforcement mechanisms.
This vulnerability maps to CWE-1035 which describes improper neutralization of special elements used in an HTML page, specifically related to iframe handling and cross-site scripting attacks. From an ATT&CK framework perspective, this corresponds to techniques involving social engineering through email and initial access via malicious attachments, with the iframe-based approach representing a sophisticated evasion technique. The vulnerability also aligns with ATT&CK's T1566 which covers "Phishing" and T1059 which addresses "Command and Scripting Interpreter" techniques, as attackers can use this method to deliver malicious payloads that execute commands on target systems.
Mitigation strategies for this vulnerability require both immediate and long-term approaches. Microsoft released patches to address the specific rendering issue in Outlook 2002, but organizations should also implement comprehensive email security measures including advanced content filtering, sandboxing of suspicious attachments, and user education about phishing threats. Network-level protections such as web application firewalls and content inspection systems can help detect and block malicious iframe references. Additionally, administrators should consider implementing strict email policies that disable iframe processing in email clients, enforce secure browsing practices, and regularly update email security solutions to address similar vulnerabilities. The vulnerability demonstrates the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies that protect against multiple attack vectors simultaneously.