CVE-2022-42809 is a high-severity vulnerability affecting Apple macOS systems, specifically related to the processing of maliciously crafted gcx files. The vulnerability stems from improper memory handling, classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). When a vulnerable macOS system processes a specially crafted gcx file, it may lead to unexpected application termination (crashes) or, more critically, arbitrary code execution. This means an attacker could potentially execute malicious code with the privileges of the targeted application, leading to full compromise of the affected system. The vulnerability requires local access (Attack Vector: Local) and user interaction (UI:R), meaning the user must open or otherwise process the malicious gcx file for exploitation to occur. No privileges are required prior to exploitation (PR:N), which lowers the barrier for an attacker who can trick a user into opening such a file. The vulnerability affects macOS versions prior to Ventura 13, where Apple has implemented improved memory handling to fix the issue. The CVSS v3.1 base score is 7.8, indicating a high severity level with impacts on confidentiality, integrity, and availability (all rated high). Although no known exploits are reported in the wild, the potential for arbitrary code execution makes this a significant threat, especially in environments where macOS is widely used. The vulnerability’s exploitation scope is unchanged (S:U), meaning the impact is confined to the vulnerable application and does not extend beyond the user’s privileges unless further privilege escalation is achieved. The vulnerability is particularly relevant to applications that handle gcx files, which may be niche but could include specialized software used in certain industries or workflows on macOS platforms.

For European organizations, the impact of CVE-2022-42809 can be substantial, especially in sectors where macOS devices are prevalent, such as creative industries, software development, education, and certain government or research institutions. Successful exploitation could lead to unauthorized code execution, resulting in data breaches, intellectual property theft, or disruption of business operations due to application crashes or system compromise. The requirement for user interaction means phishing or social engineering campaigns could be leveraged to deliver malicious gcx files, increasing the risk in organizations with less mature cybersecurity awareness. Confidentiality, integrity, and availability of sensitive data and systems could be compromised, potentially affecting compliance with GDPR and other data protection regulations. Additionally, targeted attacks against high-value European organizations using macOS could leverage this vulnerability to gain footholds in networks or exfiltrate sensitive information. Although no exploits are currently known in the wild, the high CVSS score and potential impact warrant proactive mitigation to prevent exploitation.

1. Immediate patching: Organizations should ensure all macOS devices are updated to macOS Ventura 13 or later, where the vulnerability is fixed. 2. Restrict handling of gcx files: Implement application whitelisting or file type restrictions to prevent untrusted or unknown gcx files from being opened or processed. 3. User awareness training: Educate users about the risks of opening unsolicited or suspicious files, especially gcx files, and encourage verification of file sources. 4. Endpoint protection: Deploy advanced endpoint detection and response (EDR) solutions capable of detecting anomalous behaviors related to file processing or code execution on macOS. 5. Network segmentation: Limit the ability of compromised macOS systems to access sensitive network segments to reduce lateral movement potential. 6. Monitoring and logging: Enable detailed logging of file access and application crashes related to gcx files to detect potential exploitation attempts. 7. Incident response readiness: Prepare response plans specifically for macOS-related incidents, including forensic capabilities to analyze suspicious gcx files and application crashes. These measures go beyond generic advice by focusing on the specific file type and user interaction vector, combined with macOS-specific patching and monitoring strategies.