CVE-2022-42847 is a high-severity vulnerability affecting Apple macOS, specifically addressed in macOS Ventura 13.1. The root cause is an out-of-bounds write issue, a type of memory corruption vulnerability categorized under CWE-787. This flaw allows an application to write data outside the boundaries of allocated memory, which can lead to arbitrary code execution with kernel privileges. Kernel privileges represent the highest level of access on the system, enabling an attacker to fully control the operating system, bypass security mechanisms, and potentially install persistent malware or manipulate system behavior. The vulnerability requires local access (attack vector: AV:L), does not require prior privileges (PR:N), but does require user interaction (UI:R), such as running a malicious app or triggering a crafted input. The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability (all rated high). The vulnerability scope is unchanged (S:U), meaning the exploit affects only the vulnerable component without extending to other components. No known exploits in the wild have been reported as of the publication date (December 15, 2022). The issue was resolved by Apple through improved input validation to prevent out-of-bounds writes. Since the affected versions are unspecified, it is prudent to assume all macOS versions prior to Ventura 13.1 are vulnerable. This vulnerability is critical for any environment where macOS devices are used, especially where untrusted applications can be executed by users, as it allows privilege escalation to kernel level, potentially compromising entire systems.

For European organizations, the impact of CVE-2022-42847 can be significant, particularly in sectors with widespread use of Apple macOS devices such as creative industries, education, research institutions, and enterprises that adopt macOS for endpoint devices. Successful exploitation could lead to full system compromise, allowing attackers to steal sensitive data, disrupt operations, or establish persistent footholds. The high integrity and availability impact means attackers could modify system files, disable security controls, or cause system crashes, affecting business continuity. Confidentiality breaches could expose intellectual property or personal data, raising compliance risks under GDPR. Given the requirement for user interaction, social engineering or phishing campaigns could be leveraged to trick users into executing malicious apps. The lack of known exploits in the wild suggests limited immediate risk, but the high severity and ease of local exploitation warrant proactive mitigation. Organizations with remote or hybrid workforces using macOS devices are particularly at risk if endpoint security controls are weak or if users have administrative privileges.

1. Immediate deployment of macOS Ventura 13.1 or later updates on all vulnerable devices to apply the official patch. 2. Implement application whitelisting and restrict installation of untrusted or unsigned applications to reduce the risk of malicious app execution. 3. Enforce least privilege principles by limiting user permissions and avoiding administrative rights for daily operations. 4. Educate users on the risks of running unknown applications and recognizing social engineering attempts that could lead to exploitation. 5. Employ endpoint detection and response (EDR) solutions capable of monitoring kernel-level activities and detecting anomalous behavior indicative of exploitation attempts. 6. Regularly audit and monitor macOS devices for unusual system calls or kernel module loads. 7. For organizations with macOS device management, use Mobile Device Management (MDM) tools to enforce security policies and automate patch deployment. 8. Consider network segmentation to isolate macOS devices handling sensitive data, limiting lateral movement in case of compromise. 9. Maintain up-to-date backups to enable recovery in case of system compromise or ransomware attacks leveraging this vulnerability.