CVE-2024-27853 is a vulnerability affecting Apple macOS systems prior to version Sonoma 14.4, where a maliciously crafted ZIP archive can bypass the Gatekeeper security mechanism. Gatekeeper is designed to verify the integrity and trustworthiness of downloaded software by checking digital signatures and other metadata before allowing execution. This vulnerability arises from insufficient validation of ZIP archive contents, enabling attackers to craft archives that evade these checks. By bypassing Gatekeeper, malicious software can be executed with fewer barriers, increasing the risk of compromise. The vulnerability does not require privileges or authentication but does require user interaction to open or extract the ZIP archive. The flaw impacts confidentiality and integrity by potentially allowing unauthorized code execution or data manipulation, but it does not affect system availability. Apple addressed this issue by enhancing the validation logic in macOS Sonoma 14.4, ensuring that ZIP archives are properly checked before execution is permitted. No public exploits or active attacks have been reported to date, but the vulnerability poses a risk to any macOS user who opens untrusted ZIP files. The CVSS v3.1 base score is 4.4, reflecting a medium severity with attack vector local, low complexity, no privileges required, user interaction needed, and limited impact on confidentiality and integrity.

The primary impact of CVE-2024-27853 is the potential for attackers to deliver and execute malicious code on macOS systems by bypassing Gatekeeper protections. This can lead to unauthorized access to sensitive information, data tampering, or installation of persistent malware. While the vulnerability does not directly cause denial of service or system crashes, the compromise of confidentiality and integrity can have serious consequences for individuals and organizations. Enterprises relying on macOS devices for critical operations may face increased risk of targeted attacks if users open malicious ZIP files. The requirement for user interaction limits automated exploitation but does not eliminate risk, especially in phishing or social engineering scenarios. Since Gatekeeper is a key defense layer, its bypass weakens overall endpoint security posture. Organizations with mixed environments that include macOS systems should be aware of this risk and ensure timely patching to prevent potential lateral movement or data breaches.

To mitigate CVE-2024-27853, organizations and users should promptly update all macOS devices to version Sonoma 14.4 or later, where the vulnerability is fixed. Until patching is possible, users should exercise caution when handling ZIP archives from untrusted or unknown sources, especially those received via email or downloaded from the internet. Implementing endpoint security solutions that scan compressed files for malicious content can provide an additional layer of defense. Security teams should educate users about the risks of opening unexpected attachments and encourage verification of file origins. Network-level controls such as blocking or quarantining suspicious ZIP files can reduce exposure. Monitoring for unusual file extraction or execution behavior on macOS endpoints can help detect exploitation attempts. Finally, organizations should review and enforce policies restricting software installation and execution privileges to minimize the impact of any successful bypass.