CVE-2017-13825 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.13.1 is affected. The issue involves the "CoreText" component. It allows remote attackers to execute arbitrary code or cause a denial of service (memory consumption) via a crafted font file.
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Analysis
by VulDB Data Team • 09/04/2024
The vulnerability identified as CVE-2017-13825 represents a critical security flaw within Apple's CoreText framework affecting macOS versions prior to 10.13.1. This issue demonstrates how font processing components can become entry points for sophisticated attacks, highlighting the complex security landscape surrounding rich text rendering systems. CoreText serves as a fundamental component in macOS for handling typography and text rendering, making it a prime target for attackers seeking to exploit memory handling mechanisms within the operating system's text processing pipeline.
The technical flaw manifests through improper memory handling within the CoreText component when processing specially crafted font files. Attackers can construct malicious font files that trigger buffer overflows or memory corruption conditions during the parsing process. This vulnerability falls under the CWE-121 category of Stack-based Buffer Overflow, where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The memory consumption aspect of this vulnerability can lead to denial of service conditions, while the arbitrary code execution capability provides attackers with potential system compromise opportunities. The vulnerability's exploitation typically occurs when the system automatically processes or previews font files, making it particularly dangerous in environments where users might encounter untrusted font content.
The operational impact of CVE-2017-13825 extends beyond simple system instability, representing a significant threat to user security and system integrity. Attackers can leverage this vulnerability through various attack vectors including email attachments, web downloads, or malicious websites that serve crafted font files. The remote execution capability means that users do not need to manually open the malicious files for exploitation to occur, as the system's automatic font processing features can trigger the vulnerability. This makes the attack surface particularly broad, affecting both individual users and enterprise environments where font files might be shared through various channels. The vulnerability's persistence across multiple applications that utilize CoreText for text rendering amplifies its potential impact.
Mitigation strategies for CVE-2017-13825 focus primarily on updating to macOS 10.13.1 or later versions where Apple has implemented proper bounds checking and memory management improvements. System administrators should prioritize patching affected systems and implement monitoring for unusual memory consumption patterns that might indicate exploitation attempts. The vulnerability's characteristics align with ATT&CK technique T1059.007 for Windows Scripting and T1068 for Exploitation for Privilege Escalation, though the specific implementation requires careful consideration of macOS-specific attack surfaces. Organizations should also consider implementing font file validation policies and restricting automatic font preview features in environments where security is paramount. Additionally, network-based protections such as web application firewalls and email filtering systems can help prevent delivery of malicious font files to end-user systems, while regular security audits should verify that no legacy systems remain vulnerable to this specific exploitation vector.