CVE-2017-2474 in tvOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10.3 is affected. macOS before 10.12.4 is affected. tvOS before 10.2 is affected. watchOS before 3.2 is affected. The issue involves the "Kernel" component. An off-by-one error allows attackers to execute arbitrary code in a privileged context via a crafted app.
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Analysis
by VulDB Data Team • 10/31/2024
The vulnerability identified as CVE-2017-2474 represents a critical kernel-level flaw affecting multiple Apple operating systems including iOS versions prior to 10.3, macOS versions prior to 10.12.4, tvOS versions prior to 10.2, and watchOS versions prior to 3.2. This issue resides within the kernel component of Apple's operating systems, which serves as the core foundation for system operations and security enforcement. The vulnerability stems from an off-by-one error, a common programming flaw that occurs when a loop or array access extends beyond its valid boundaries by a single element. Such errors typically arise from improper boundary condition checks in code logic where developers fail to account for inclusive or exclusive boundary scenarios.
The technical nature of this vulnerability allows attackers to exploit a privilege escalation vector through a crafted application that manipulates memory boundaries in the kernel space. An off-by-one error in kernel code creates a situation where memory access can extend beyond allocated buffer boundaries, potentially allowing an attacker to overwrite adjacent memory locations or access protected kernel data structures. This type of vulnerability falls under the CWE-129 category of "Improper Validation of Array Index" and specifically relates to the broader class of buffer overflow conditions that can lead to arbitrary code execution. The vulnerability's exploitation requires the attacker to have a legitimate application installed on the target system, which then serves as a vehicle to trigger the kernel-level memory corruption that results in privilege escalation.
The operational impact of CVE-2017-2474 is severe and potentially devastating for affected systems, as it enables attackers to execute arbitrary code with kernel-level privileges. This means that an attacker who successfully exploits this vulnerability can gain complete control over the affected device, bypassing all security mechanisms and potentially accessing sensitive user data, modifying system files, or establishing persistent backdoors. The attack vector requires the victim to install and run a malicious application, which aligns with the ATT&CK framework's technique T1059.001 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation. The vulnerability essentially transforms a regular application into a kernel-level attack vector, making it particularly dangerous as it can be exploited through seemingly legitimate applications.
Mitigation strategies for this vulnerability primarily involve applying the official security updates released by Apple, which address the kernel-level memory handling issue through proper boundary validation and array index checking. System administrators and users should immediately install the latest security patches for their respective operating systems, including iOS 10.3, macOS 10.12.4, tvOS 10.2, and watchOS 3.2. Additionally, organizations should implement application whitelisting policies to prevent unauthorized applications from being installed on critical systems, as this vulnerability requires a malicious app to be present on the device for exploitation to occur. The security community has classified this vulnerability as high severity, and its exploitation has been documented in various threat intelligence reports, emphasizing the importance of prompt remediation and monitoring for potential exploitation attempts.