CVE-2002-0832 in Internet Explorer
Summary
by MITRE
Internet Explorer 5, 5.6, and 6 allows remote attackers to bypass cookie privacy settings and store information across browser sessions via the userData (storeuserData) feature.
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Analysis
by VulDB Data Team • 05/07/2019
The vulnerability identified as CVE-2002-0832 represents a critical security flaw in Microsoft Internet Explorer versions 5, 5.6, and 6 that fundamentally undermines user privacy protections. This issue specifically targets the browser's cookie management system, which is designed to control how web applications store and retrieve user data across different browsing sessions. The flaw exploits the userData feature, a client-side storage mechanism that was intended to provide persistent data storage capabilities for web applications, but was implemented in a manner that circumvented existing privacy controls. The vulnerability operates by allowing malicious web pages to store data in a way that persists beyond the normal cookie expiration times and privacy restrictions, effectively creating a backdoor for persistent tracking and data collection.
From a technical perspective, this vulnerability stems from improper validation and enforcement of privacy boundaries within Internet Explorer's implementation of the userData storage mechanism. The userData feature was designed to provide a way for web applications to store data locally on the user's machine, but the implementation failed to properly respect the cookie privacy settings that users had configured. This flaw specifically affects how the browser handles the storeuserData method, which allows web applications to persistently store data without proper user consent or awareness. The technical implementation does not adequately distinguish between different privacy levels or respect the user's configured privacy preferences, enabling malicious actors to bypass these protections through crafted web content. The vulnerability essentially creates a persistent storage mechanism that operates outside the normal cookie management framework, allowing for long-term data retention that should have been restricted by privacy settings.
The operational impact of this vulnerability is significant as it enables persistent tracking of user activities across multiple browsing sessions, effectively nullifying the privacy protections that users expect from their browser settings. Attackers can exploit this vulnerability to store information that persists even after users believe they have cleared their cookies or adjusted their privacy settings. This capability allows for sophisticated tracking mechanisms that can monitor user behavior over extended periods, potentially collecting sensitive information about browsing habits, preferences, and personal data. The vulnerability affects users who may have configured their browsers to limit cookie storage or to clear cookies upon session termination, but the userData feature allows persistent storage that bypasses these protections entirely. This creates a situation where users believe they have maintained privacy but are unknowingly subject to long-term tracking by malicious websites.
Security professionals should understand this vulnerability in the context of the CWE (Common Weakness Enumeration) classification system, where this flaw would be categorized under CWE-200, "Information Exposure," and potentially CWE-312, "Cleartext Storage of Sensitive Information." The vulnerability also aligns with ATT&CK techniques related to credential access and persistence, as it enables long-term data collection that can be used to reconstruct user profiles and behaviors over time. Organizations should implement immediate mitigations including updating to supported browser versions, implementing network-level controls to restrict access to potentially malicious sites, and educating users about the importance of keeping their browsers updated. Additionally, security monitoring should include detection of suspicious userData storage patterns and implementation of browser security policies that restrict the use of potentially problematic client-side storage mechanisms. The vulnerability highlights the critical importance of proper input validation and access control implementation in web browser security features, as well as the necessity of maintaining up-to-date security practices to protect against known vulnerabilities that could be exploited for persistent tracking and data collection.