CVE-2016-7618 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.12.2 is affected. The issue involves the "Foundation" component. It allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via a crafted .gcx file.
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Analysis
by VulDB Data Team • 09/20/2024
The vulnerability identified as CVE-2016-7618 represents a critical security flaw within Apple's macOS operating system affecting versions prior to 10.12.2. This issue resides within the Foundation framework, which serves as a core component of Apple's software ecosystem providing fundamental functionalities for application development and system operations. The Foundation framework handles essential tasks including data management, file operations, and memory handling, making it a prime target for attackers seeking to compromise system integrity. The vulnerability specifically manifests when the system processes maliciously crafted .gcx files, which are typically used for storing graphics context information in Apple's Core Graphics framework. This particular flaw demonstrates how seemingly innocuous file processing operations can become vectors for severe security breaches when proper input validation and memory management protocols are absent or inadequate.
The technical nature of this vulnerability stems from improper memory handling within the Foundation component's processing of .gcx files. When a malicious .gcx file is encountered, the system's memory management routines fail to properly validate the file structure, leading to memory corruption that can result in arbitrary code execution or application crashes. This type of vulnerability falls under the CWE-125 vulnerability category, which describes "Out-of-Bounds Read" conditions where programs access memory locations beyond their allocated boundaries. The flaw operates by exploiting a buffer overflow or similar memory corruption mechanism that allows attackers to manipulate the program's execution flow. The attack vector is particularly concerning because it requires no user interaction beyond the simple act of opening or processing the malicious file, making it an ideal candidate for remote exploitation scenarios. Attackers can craft .gcx files with malformed data structures that, when processed by the vulnerable Foundation component, trigger memory corruption and potentially allow for privilege escalation or complete system compromise.
The operational impact of CVE-2016-7618 extends beyond simple denial of service conditions to encompass serious security risks that could affect enterprise environments and individual users alike. Organizations running macOS versions prior to 10.12.2 face significant exposure to remote code execution attacks that could enable attackers to install malware, exfiltrate sensitive data, or establish persistent backdoors within their systems. The vulnerability's potential for causing application crashes also creates opportunities for denial of service attacks that could disrupt critical business operations. From an attacker's perspective, this vulnerability aligns with the MITRE ATT&CK framework's technique T1059, which covers "Command and Scripting Interpreter" where adversaries can leverage system vulnerabilities to execute malicious code. The lack of user interaction requirements makes this attack vector particularly dangerous in targeted campaigns where attackers can deliver malicious .gcx files through email attachments, web downloads, or compromised websites. The vulnerability's exploitation capability represents a significant risk to Apple's security model, as it demonstrates how core system components can be compromised through file processing operations.
Organizations and users should immediately implement mitigations to address this vulnerability by upgrading to macOS 10.12.2 or later versions where Apple has provided patches to address the memory handling issues within the Foundation framework. The patch addresses the root cause by implementing proper input validation and memory boundary checks when processing .gcx files, preventing the memory corruption that enables arbitrary code execution. System administrators should also consider implementing additional security controls such as sandboxing mechanisms and file type restrictions to limit the potential impact of similar vulnerabilities. The vulnerability highlights the importance of maintaining up-to-date security patches and demonstrates how even core system frameworks can contain critical flaws that require immediate attention. Security monitoring should include detection of suspicious file processing activities and unusual memory allocation patterns that might indicate exploitation attempts. Apple's security advisory for this vulnerability emphasizes the need for proactive patch management, as the flaw represents a serious threat to system integrity that could be exploited in advanced persistent threat campaigns. The remediation process should also include user education about the risks of opening untrusted files and the importance of maintaining current operating system versions to protect against known vulnerabilities.