CVE-2012-0640 in Safari
Summary
by MITRE
WebKit in Apple Safari before 5.1.4 does not properly implement "From third parties and advertisers" cookie blocking, which makes it easier for remote web servers to track users via a cookie.
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Analysis
by VulDB Data Team • 03/22/2021
The vulnerability identified as CVE-2012-0640 represents a significant privacy flaw in Apple Safari's WebKit rendering engine that affected versions prior to 5.1.4. This issue stems from the improper implementation of cookie blocking mechanisms specifically designed to protect user privacy when interacting with third-party content and advertisements. The flaw allows malicious remote web servers to circumvent Safari's intended cookie restrictions, enabling persistent tracking of user activities across different websites and sessions.
The technical implementation flaw occurs within Safari's WebKit component where the "From third parties and advertisers" cookie blocking setting fails to properly enforce its intended restrictions. This vulnerability specifically affects how Safari handles third-party cookies, which are typically blocked to prevent cross-site tracking by advertisers and other third-party entities. The improper implementation creates a scenario where remote servers can set cookies that would normally be restricted, effectively bypassing the user's privacy controls and allowing for continuous user profiling and tracking.
From an operational impact perspective, this vulnerability exposes users to extensive tracking capabilities that undermine their privacy expectations and browsing security. Attackers can leverage this flaw to maintain persistent user sessions across different domains, build detailed behavioral profiles, and potentially correlate user activities over extended periods. The vulnerability essentially transforms Safari's privacy protection mechanisms into ineffective barriers, allowing third-party trackers to operate with minimal restrictions and potentially enabling more sophisticated tracking techniques such as fingerprinting and cross-site user correlation.
The security implications of CVE-2012-0640 align with CWE-384, which addresses the improper implementation of security features, specifically focusing on the inadequate enforcement of privacy controls. This vulnerability also maps to ATT&CK technique T1566, which covers credential harvesting through social engineering, as the tracking capabilities enabled by this flaw can be used to gather sensitive user information over time. The flaw demonstrates a critical gap in Safari's cookie management system that undermines the browser's privacy protection architecture and creates opportunities for persistent surveillance.
Mitigation strategies for this vulnerability require immediate patching of Safari to version 5.1.4 or later, which contains the corrected cookie blocking implementation. Users should also consider implementing additional privacy protections such as browser extensions that provide enhanced cookie management, regular clearing of browser data, and using privacy-focused browsers or configurations. Organizations should conduct security assessments to identify potential exploitation of this vulnerability in their environments and ensure all Safari installations are updated to versions that properly implement the cookie blocking mechanisms. The vulnerability highlights the importance of thorough security testing of privacy features and the critical need for proper enforcement of security controls in web browsers.