CVE-2017-13879 in iOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11.2 is affected. The issue involves the "IOMobileFrameBuffer" component. It allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app.
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Analysis
by VulDB Data Team • 01/26/2021
The vulnerability identified as CVE-2017-13879 represents a critical security flaw within Apple's iOS operating system affecting versions prior to 11.2. This issue resides within the IOMobileFrameBuffer component, which serves as a crucial interface for managing display frame buffers on mobile devices. The vulnerability stems from improper input validation and memory handling within this privileged system component, creating a pathway for malicious actors to escalate their privileges and execute arbitrary code with system-level permissions. The flaw demonstrates characteristics consistent with heap-based buffer overflow conditions that can lead to memory corruption and unauthorized system access.
The technical exploitation of this vulnerability occurs through a specially crafted application that manipulates the IOMobileFrameBuffer component during display rendering operations. When such an application is executed, it can trigger memory corruption within the kernel-level frame buffer management system, allowing attackers to bypass normal security boundaries and gain elevated privileges. This type of vulnerability falls under the CWE-121 category of "Stack-based Buffer Overflow" and aligns with ATT&CK technique T1068 which describes "Exploitation for Privilege Escalation." The attack vector leverages the fact that the frame buffer component operates with high privileges and lacks adequate bounds checking for incoming data, creating a window for malicious input to corrupt memory structures and potentially execute malicious code.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can result in complete system compromise and persistent access to affected devices. Attackers who successfully exploit this vulnerability can execute arbitrary code in a privileged context, potentially leading to data theft, persistent backdoor installation, or complete device control. The memory corruption aspect of the flaw can also cause denial of service conditions, rendering affected devices unusable and potentially requiring complete system restoration. This vulnerability particularly affects iOS devices running versions 11.1 and earlier, making them susceptible to attacks that could compromise user data and device integrity. The exploitation requires only a malicious application, making it particularly dangerous as it can be delivered through normal app distribution channels without requiring physical access or specialized attack infrastructure.
Organizations and individual users should immediately update to iOS 11.2 or later to remediate this vulnerability, as Apple released a security update specifically addressing this flaw. System administrators should implement comprehensive monitoring for suspicious application behavior and ensure all iOS devices within their environment are kept current with security patches. The vulnerability highlights the importance of proper input validation in kernel-level components and demonstrates why privileged system interfaces require rigorous security testing and code review processes. Security teams should also consider implementing application whitelisting policies to prevent installation of untrusted applications that could potentially exploit this or similar vulnerabilities. The incident underscores the necessity of maintaining current security patches and the potential consequences of running outdated software versions in enterprise and personal environments.