CVE-2017-13888 in iOS
Summary
by MITRE
In iOS before 11.2, a type confusion issue was addressed with improved memory handling.
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Analysis
by VulDB Data Team • 04/28/2020
The vulnerability identified as CVE-2017-13888 represents a critical type confusion flaw present in iOS versions prior to 11.2, specifically affecting the operating system's memory management mechanisms. This issue stems from inadequate type checking during runtime operations, where the system fails to properly validate data types when processing memory operations. The vulnerability manifests when the iOS kernel or system processes encounter situations where memory objects are incorrectly interpreted as different data types than originally allocated, creating a dangerous condition that can be exploited by malicious actors.
The technical root cause of this type confusion vulnerability aligns with CWE-466, which classifies improper handling of pointer types and memory objects. When the system processes memory operations, it fails to maintain proper type boundaries between different object categories, allowing attackers to manipulate memory in ways that bypass normal security checks. This particular flaw occurs within the kernel's memory management subsystem where type information is not consistently verified during object allocation and deallocation cycles. The vulnerability enables attackers to potentially execute arbitrary code by crafting malicious inputs that exploit the incorrect type handling, leading to privilege escalation and system compromise.
The operational impact of CVE-2017-13888 extends beyond simple memory corruption, as it provides attackers with a pathway to achieve code execution within the iOS kernel space. This vulnerability can be exploited through various attack vectors including malicious web content, email attachments, or compromised applications that leverage the type confusion to gain elevated privileges. The flaw particularly affects the system's ability to properly handle memory objects during processing, creating opportunities for attackers to manipulate system behavior and potentially access sensitive user data or system resources. Security researchers have noted that this vulnerability could be leveraged to bypass security mechanisms such as code signing checks and sandbox restrictions, making it particularly dangerous for mobile environments.
Mitigation strategies for this vulnerability primarily focus on updating to iOS version 11.2 or later, where Apple implemented improved memory handling techniques and enhanced type validation mechanisms. The patch addresses the core issue by strengthening type checking routines within the kernel memory management system, ensuring that objects maintain their intended data types throughout their lifecycle. Organizations should also implement network monitoring to detect potential exploitation attempts and consider deploying mobile device management solutions that enforce timely security updates. From an ATT&CK framework perspective, this vulnerability maps to techniques such as T1068 for local privilege escalation and T1203 for exploitation of memory corruption vulnerabilities, highlighting the need for comprehensive endpoint protection measures. The fix demonstrates Apple's approach to addressing memory safety issues through improved heap management and enhanced runtime type checking, aligning with industry best practices for preventing similar type confusion vulnerabilities in mobile operating systems.