CVE-2015-8079 in Qt
Summary
by MITRE
qt5-qtwebkit before 5.4 records private browsing URLs to its favicon database, WebpageIcons.db.
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Analysis
by VulDB Data Team • 06/26/2022
The vulnerability identified as CVE-2015-8079 affects qt5-qtwebkit versions prior to 5.4 and represents a significant privacy disclosure issue within web browser implementations. This flaw specifically impacts the handling of private browsing sessions where users expect their navigation history and associated metadata to remain completely isolated from regular browsing activities. The vulnerability arises from the improper management of favicon database storage during private browsing mode, creating a persistent data leak that undermines user privacy expectations.
The technical implementation flaw occurs within the WebpageIcons.db database file where private browsing URLs are inadvertently recorded despite the user's intention to maintain anonymity during private sessions. This database mechanism, designed to store favicon information for web pages, fails to distinguish between regular and private browsing contexts, resulting in the storage of sensitive URL information that should remain private. The issue demonstrates a lack of proper session isolation mechanisms and inadequate data handling procedures for privacy-sensitive operations.
From an operational impact perspective, this vulnerability creates a persistent privacy leak that allows unauthorized parties to reconstruct user navigation patterns and web activity even during private browsing sessions. The stored URLs in the favicon database can be accessed by anyone with system-level access to the database file, effectively nullifying the privacy protections that private browsing is designed to provide. This exposure represents a critical weakness in the browser's security model and can be exploited by malware, system administrators, or attackers with local access to recover sensitive browsing information.
The vulnerability aligns with CWE-200, which addresses information exposure, and represents a specific implementation flaw in privacy protection mechanisms. From an ATT&CK framework perspective, this issue maps to T1566, technique for credential access through information gathering, as it enables adversaries to collect sensitive browsing information that could lead to further exploitation. The flaw also relates to T1070, which covers indicator removal and data manipulation, as the persistent storage of private browsing data creates artifacts that can be used for forensic analysis.
Organizations and users should immediately update to qt5-qtwebkit version 5.4 or later, which contains the necessary patches to address this privacy leak. System administrators should implement monitoring for unauthorized access to WebpageIcons.db files and consider implementing additional access controls. Users should be educated about the importance of keeping their browser software updated and should avoid using older versions of qt5-qtwebkit in environments where privacy is critical. The vulnerability serves as a reminder of the importance of proper session isolation and data handling in privacy-sensitive applications, particularly in web browser implementations where user expectations of confidentiality are paramount.