CVE-2015-1090 in iOS
Summary
by MITRE
CFNetwork in Apple iOS before 8.3 does not delete HTTP Strict Transport Security (HSTS) state information in response to a Safari history-clearing action, which allows attackers to obtain sensitive information by reading a history file.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 05/03/2022
The vulnerability identified as CVE-2015-1090 represents a critical security flaw in Apple iOS versions prior to 8.3 where the CFNetwork framework fails to properly clear HTTP Strict Transport Security HSTS state information when users perform history-clearing operations through Safari. This issue stems from inadequate handling of security state persistence within the mobile operating system's network stack. The flaw specifically affects how the system manages security credentials and state information that should be purged during user-initiated privacy cleanup operations, creating a persistent security risk that extends beyond the intended scope of user privacy controls.
Technical exploitation of this vulnerability occurs through the manipulation of Safari's history clearing functionality, where attackers can observe that HSTS state information remains accessible even after users believe they have cleared their browsing history. The underlying mechanism involves the persistence of security-related metadata that should be automatically removed during history cleanup operations, allowing malicious actors to potentially reconstruct user browsing patterns and access sensitive information that was previously considered secure. This represents a failure in proper state management and memory cleanup procedures within the CFNetwork implementation, which is classified as a CWE-200 information exposure vulnerability.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to potentially reconstruct user navigation patterns and access previously visited secure websites without requiring additional authentication or exploitation techniques. When users clear their browsing history through Safari, they expect all related security state information to be removed, but this vulnerability allows persistent tracking of secure web interactions. The attack vector leverages the fundamental assumption that history clearing operations will properly sanitize all associated security state, creating a persistent surveillance capability that undermines user privacy expectations and the security model of the iOS platform.
Security implications of this vulnerability align with ATT&CK technique T1566.001 targeting credential access through web application attacks and T1070.004 focusing on clearing event logs and system artifacts. The flaw enables attackers to maintain knowledge of previously visited HTTPS sites and potentially reconstruct user behavior patterns, which could be combined with other reconnaissance techniques to build comprehensive profiles of user activities. Organizations should consider this vulnerability as part of broader mobile device security assessments, particularly in environments where sensitive information access and privacy protection are critical concerns. The remediation approach requires updating to iOS 8.3 or later versions where Apple implemented proper HSTS state clearing mechanisms, along with implementing additional network monitoring to detect anomalous behavior patterns that might indicate exploitation attempts.
This vulnerability demonstrates the importance of comprehensive state management in security-critical components and highlights the need for thorough testing of privacy-related functionality. The issue represents a failure in proper information lifecycle management where security state information should be automatically purged during user-initiated privacy operations, creating a persistent security risk that could be exploited for long-term surveillance or targeted attacks. The vulnerability also underscores the importance of adhering to security standards such as those defined in the OWASP Mobile Top 10 and NIST cybersecurity frameworks, where proper state management and information sanitization are fundamental requirements for protecting user privacy and security.