CVE-2017-2406 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 "FontParser" component. It allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted font file.
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Analysis
by VulDB Data Team • 10/28/2024
The vulnerability identified as CVE-2017-2406 represents a critical security flaw within Apple's font parsing infrastructure affecting multiple operating systems including iOS, macOS, tvOS, and watchOS. This issue resides within the FontParser component which is responsible for processing and rendering font files within Apple's ecosystem. The vulnerability stems from inadequate input validation and memory handling mechanisms when processing specially crafted font files, creating a pathway for malicious actors to exploit the system through seemingly benign font data.
The technical nature of this flaw manifests as a memory corruption vulnerability that can be triggered through the processing of malformed font files. When the FontParser component encounters a crafted font file, it fails to properly validate the file structure and memory allocation, leading to unpredictable behavior that can result in either arbitrary code execution or denial of service conditions. This vulnerability operates at the intersection of multiple cybersecurity domains including code execution, memory corruption, and privilege escalation threats. The flaw aligns with CWE-125, which describes out-of-bounds read vulnerabilities, and CWE-787, which covers out-of-bounds writes, both of which are common in font processing libraries due to the complex and varied nature of font file formats.
The operational impact of this vulnerability extends across Apple's entire product portfolio, affecting users of iOS devices prior to version 10.3, macOS systems before 10.12.4, tvOS devices before 10.2, and watchOS devices before 3.2. Attackers could potentially deliver malicious font files through various vectors including email attachments, web downloads, or compromised websites, making this a particularly dangerous vulnerability for widespread exploitation. The remote code execution capability means that successful exploitation could allow attackers to gain full control of affected devices, potentially leading to data theft, persistent backdoor installation, or further network infiltration. Additionally, the denial of service component of this vulnerability could be used to disrupt services or cause application crashes, creating availability issues for users and potentially enabling more sophisticated attack vectors.
The exploitation of this vulnerability follows established patterns found in the ATT&CK framework under the T1059.007 technique for process injection and T1068 for exploit development. Security professionals should note that this vulnerability demonstrates the inherent risks associated with rich media processing components in operating systems, as font files are frequently encountered in legitimate use cases but can serve as attack vectors due to their complex parsing requirements. Organizations should implement immediate mitigations including prompt deployment of Apple's security updates, network segmentation to prevent unauthorized font file delivery, and enhanced monitoring for suspicious font-related activities. The vulnerability also underscores the importance of robust input validation and memory safety practices in font processing libraries, as highlighted in industry best practices for preventing similar issues in other software components.