CVE-2015-5885 in Watch
Summary
by MITRE
The CFNetwork Cookies component in Apple iOS before 9 allows remote attackers to track users via vectors involving a cookie for a top-level domain.
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Analysis
by VulDB Data Team • 11/21/2024
The vulnerability identified as CVE-2015-5885 resides within Apple iOS versions prior to 9.0, specifically affecting the CFNetwork Cookies component. This flaw represents a significant privacy concern that enables remote attackers to conduct persistent user tracking through sophisticated cookie manipulation techniques. The vulnerability stems from how iOS handles cookie storage and transmission for top-level domain cookies, creating an exploitable condition that undermines user privacy and tracking resistance. The issue manifests when cookies are set for top-level domains rather than subdomains, allowing malicious actors to maintain persistent tracking mechanisms across different websites within the same domain hierarchy.
The technical implementation of this vulnerability involves improper cookie scope handling within the CFNetwork framework, which governs network operations including HTTP cookie management. When a cookie is set for a top-level domain such as .com or .org, the system fails to properly isolate these cookies from subdomain contexts, creating a cross-site tracking vector. This behavior violates standard cookie security practices and allows attackers to establish tracking mechanisms that persist beyond typical session boundaries. The flaw operates at the network protocol level, leveraging the underlying HTTP cookie specification while exploiting iOS's specific implementation of cookie storage policies. Security researchers have classified this issue under CWE-276, which addresses improper privileges and access control, as the vulnerability enables unauthorized tracking capabilities through legitimate network operations.
The operational impact of CVE-2015-5885 extends beyond simple privacy concerns to encompass potential data harvesting and user behavior analysis capabilities. Attackers can leverage this vulnerability to create persistent tracking mechanisms that monitor user activities across multiple websites within the same top-level domain, effectively bypassing typical privacy protections. This tracking capability can be exploited for targeted advertising, behavioral profiling, or more nefarious purposes including identity theft and surveillance. The vulnerability's persistence across different applications and services that utilize CFNetwork makes it particularly dangerous as it affects the entire iOS ecosystem rather than isolated components. Users may remain unaware of this tracking activity as it operates at the system level within the network stack, making detection and mitigation challenging for end users who lack visibility into these low-level operations.
Mitigation strategies for this vulnerability require immediate system updates to iOS 9.0 or later versions where Apple has implemented proper cookie scope enforcement and improved cookie handling mechanisms. Organizations should also consider network-level monitoring solutions that can detect anomalous cookie behavior patterns and implement additional privacy controls such as cookie blocking or strict tracking protection measures. The remediation process involves not only updating the operating system but also ensuring that applications and services within the iOS environment properly handle cookie operations according to updated security guidelines. Security teams should conduct comprehensive vulnerability assessments to identify any applications that may be leveraging the vulnerable CFNetwork component and ensure proper cookie management practices are implemented. This vulnerability demonstrates the critical importance of proper cookie security implementation and highlights the need for robust privacy controls in mobile operating systems, particularly when dealing with cross-domain tracking mechanisms that can persist across multiple user sessions and application contexts.