CVE-2015-1127 in Safari
Summary
by MITRE
The private-browsing implementation in WebKit in Apple Safari before 6.2.5, 7.x before 7.1.5, and 8.x before 8.0.5 places browsing history into an index, which might allow local users to obtain sensitive information by reading index entries.
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Analysis
by VulDB Data Team • 05/03/2022
The vulnerability identified as CVE-2015-1127 represents a critical privacy flaw in Apple Safari's private browsing implementation within the WebKit rendering engine. This security issue affects multiple versions of Safari including those before 6.2.5, 7.x versions before 7.1.5, and 8.x versions before 8.0.5, demonstrating a fundamental weakness in how the browser handles sensitive user data during private browsing sessions. The flaw stems from improper handling of browsing history data within the index structure, creating a persistent exposure that undermines the core purpose of private browsing modes.
The technical implementation flaw occurs when Safari's private browsing mode fails to adequately isolate browsing history data from the index system that tracks user activity. During private browsing sessions, the browser should maintain complete separation between user activities and system indexing mechanisms. However, this vulnerability allows the system to place private browsing history into an index structure, effectively creating a persistent record that can be accessed through index entries. The underlying issue relates to improper data handling and memory management within WebKit's private browsing subsystem, where sensitive information remains accessible through system-level index mechanisms despite the user's intent to maintain privacy.
The operational impact of this vulnerability extends beyond simple privacy concerns to potentially enable sophisticated attacks against user confidentiality. Local users with access to the system can exploit this weakness to read index entries and recover sensitive browsing information that should have been completely isolated during private browsing sessions. This creates a significant risk for users who rely on private browsing for protecting sensitive activities such as financial transactions, medical research, or personal communications. The vulnerability essentially defeats the purpose of private browsing by providing a backdoor access mechanism that bypasses the intended privacy protections, making it particularly dangerous for users who believe their browsing activities are completely hidden from system-level monitoring.
From a cybersecurity perspective, this vulnerability aligns with CWE-200, which addresses "Information Exposure," and demonstrates characteristics consistent with ATT&CK technique T1566, "Phishing," as it could enable attackers to gather sensitive information about user activities. The flaw represents a classic case of insufficient access control where the system fails to properly enforce the boundaries between private and public data access. Security professionals should consider this vulnerability when evaluating the effectiveness of privacy controls in web browsers and recommend immediate patching of affected Safari versions. The remediation approach requires comprehensive system updates that address the core index management issue within WebKit's private browsing implementation, ensuring that browsing history data cannot be accessed through index entries regardless of the browsing mode used. Organizations should prioritize this update to prevent potential exploitation that could lead to unauthorized access to sensitive user information and compromise user privacy guarantees.