CVE-2015-7018 in Mac OS X
Summary
by MITRE
FontParser in Apple iOS before 9.1 and OS X before 10.11.1 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted font file, a different vulnerability than CVE-2015-6976, CVE-2015-6977, CVE-2015-6978, CVE-2015-6990, CVE-2015-6991, CVE-2015-6993, CVE-2015-7008, CVE-2015-7009, and CVE-2015-7010.
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Analysis
by VulDB Data Team • 11/19/2024
The vulnerability identified as CVE-2015-7018 represents a critical memory corruption flaw within Apple's FontParser component that affects iOS versions prior to 9.1 and OS X versions prior to 10.11.1. This vulnerability resides in the font parsing functionality that processes various font file formats including TrueType, OpenType, and other embedded font types that are commonly encountered in digital documents, web content, and system resources. The flaw specifically manifests when the system processes maliciously crafted font files that exploit improper memory handling during the parsing operations. According to the Common Weakness Enumeration framework, this vulnerability maps to CWE-125: "Out-of-bounds Read" and CWE-787: "Out-of-bounds Write", indicating that the memory corruption occurs through either reading or writing beyond allocated memory boundaries during font file processing.
The technical exploitation of CVE-2015-7018 occurs when a remote attacker crafts a specially designed font file that contains malformed data structures or excessive memory allocations that cause the FontParser to overflow memory buffers or corrupt memory regions. This memory corruption can be leveraged to execute arbitrary code with the privileges of the affected application or system process. The vulnerability is particularly dangerous because font files are frequently encountered in legitimate contexts such as email attachments, web pages, PDF documents, and application installations, making it trivial for attackers to deliver malicious payloads through seemingly benign files. The attack vector operates through the standard font rendering pipeline where applications and system components load and process font resources, making this a widespread potential attack surface across multiple application types.
The operational impact of this vulnerability extends beyond simple remote code execution to include potential denial of service conditions that can crash system processes or render applications unstable. When exploited successfully, the memory corruption can cause kernel panics, application crashes, or complete system hangs that require manual intervention to recover. The vulnerability affects a broad range of Apple products including iPhones, iPads, Mac computers, and potentially other Apple devices that utilize the affected font parsing libraries. Security researchers have noted that this vulnerability shares characteristics with other font-related vulnerabilities in the same timeframe, but operates through distinct memory handling flaws that distinguish it from CVE-2015-6976 through CVE-2015-7010, indicating a pattern of memory safety issues within Apple's font processing components.
Organizations and users must implement immediate mitigation strategies including applying the official security patches released by Apple for iOS 9.1 and OS X 10.11.1, which address the memory corruption issues in the FontParser. System administrators should also consider implementing network-based controls such as content filtering and email scanning to prevent the delivery of potentially malicious font files through common attack vectors. The vulnerability demonstrates the importance of input validation and memory safety practices as outlined in the MITRE ATT&CK framework's technique T1059.007 for "Command and Scripting Interpreter: JavaScript' and T1203 for 'Exploitation for Client Execution'. Additionally, organizations should consider implementing application sandboxing and privilege separation techniques to limit the potential impact of successful exploitation attempts. Regular security monitoring and vulnerability assessment programs should be enhanced to detect and prevent the use of vulnerable font processing libraries in enterprise environments.