CVE-2017-2450 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 "CoreText" component. It allows remote attackers to obtain sensitive information or cause a denial of service (out-of-bounds read and application crash) via a crafted font file.
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Analysis
by VulDB Data Team • 10/27/2024
The vulnerability identified as CVE-2017-2450 represents a critical security flaw within Apple's CoreText framework that affects multiple operating systems including iOS, macOS, tvOS, and watchOS. This issue stems from improper input validation within the font processing subsystem, specifically when handling crafted font files that contain malformed data structures. The vulnerability manifests as an out-of-bounds read condition that can be exploited by remote attackers to either extract sensitive information from system memory or trigger application crashes that result in denial of service conditions.
The technical exploitation of this vulnerability occurs through the manipulation of font files that are processed by the CoreText component, which is responsible for text rendering across Apple's ecosystem. When a maliciously crafted font file is loaded, the CoreText framework fails to properly validate the font's internal structure, leading to memory access violations that can be leveraged to read beyond allocated memory boundaries. This flaw falls under the CWE-125 vulnerability category, which specifically addresses out-of-bounds read conditions that can result in information disclosure and system instability. The vulnerability's impact is particularly concerning because CoreText is deeply integrated into Apple's operating systems and is used extensively throughout the user interface, making it an attractive target for attackers seeking to compromise system integrity.
The operational implications of CVE-2017-2450 extend beyond simple denial of service scenarios, as the vulnerability can potentially enable information disclosure attacks that may expose sensitive data stored in memory. Attackers can craft font files that, when processed by affected systems, trigger memory read operations that reveal contents of system memory, including potentially sensitive information such as cryptographic keys, user credentials, or application data. This vulnerability also aligns with ATT&CK technique T1059.007, which covers the use of scripting languages for execution, as attackers may leverage font-based delivery mechanisms to execute malicious code or gather intelligence from compromised systems. The widespread adoption of Apple's CoreText framework across multiple platforms increases the attack surface significantly, as a single malicious font file could potentially compromise devices running different operating systems.
Mitigation strategies for CVE-2017-2450 focus primarily on applying the official security updates released by Apple, which include patches that strengthen input validation within the CoreText component. Organizations should prioritize updating all affected systems to the latest versions of iOS 10.3, macOS 10.12.4, tvOS 10.2, and watchOS 3.2, as these releases contain the necessary fixes to address the out-of-bounds read conditions. Additionally, network administrators should implement defensive measures such as font file filtering at network boundaries, particularly in environments where users may encounter untrusted font content from external sources. The vulnerability serves as a reminder of the critical importance of proper input validation in system components that process user-supplied data, as even seemingly benign file formats like fonts can become attack vectors when proper security controls are not implemented. Security teams should also monitor for potential exploitation attempts through network traffic analysis and implement appropriate intrusion detection measures to identify and block malicious font file delivery attempts.