CVE-2025-31244 is a vulnerability in Apple macOS related to a file quarantine bypass that allows an application to break out of its sandbox environment. The sandbox is a critical security mechanism that restricts app capabilities and access to system resources, thereby limiting the damage a malicious or compromised app can cause. This vulnerability stems from insufficient checks in the file quarantine mechanism, which is designed to prevent untrusted or downloaded files from executing without scrutiny. By bypassing quarantine, a malicious app can escape sandbox restrictions, potentially gaining unauthorized access to system resources, sensitive data, or executing arbitrary code with elevated privileges. The issue was addressed in macOS Sequoia 15.5 by adding additional verification steps to the quarantine process, effectively closing the bypass. The CVSS 3.1 score of 8.8 reflects a high-severity flaw with low attack complexity, requiring limited privileges (PR:L) but no user interaction (UI:N), and it affects confidentiality, integrity, and availability (all high impact). The scope is changed (S:C), meaning the vulnerability affects components beyond the initially vulnerable component, increasing the risk. Although no exploits are currently known in the wild, the potential for exploitation is significant given the nature of sandbox escapes. This vulnerability is classified under CWE-693 (Protection Mechanism Failure), indicating a failure in enforcing security boundaries. Organizations running macOS versions prior to 15.5 are vulnerable and should prioritize patching. The lack of detailed affected versions suggests a broad impact across multiple macOS releases before 15.5. This vulnerability is particularly concerning for environments where macOS is used for sensitive operations, as sandbox escapes can lead to full system compromise.

For European organizations, the impact of CVE-2025-31244 can be substantial. The ability for an app to break out of its sandbox undermines one of the core security controls in macOS, potentially allowing attackers to access sensitive data, install persistent malware, or disrupt system operations. This can lead to data breaches, intellectual property theft, and operational downtime. Sectors such as finance, healthcare, government, and critical infrastructure, which often use macOS devices for secure communications and operations, are at heightened risk. The high CVSS score indicates that confidentiality, integrity, and availability could all be severely impacted. Additionally, since the attack complexity is low and no user interaction is required, the threat actor could exploit this vulnerability remotely or via malicious software distribution channels without needing to trick users. This elevates the risk of widespread exploitation if the vulnerability is weaponized. The absence of known exploits in the wild currently provides a window for proactive defense, but organizations must act swiftly to patch and monitor for suspicious activity. Failure to address this vulnerability could result in significant regulatory and reputational damage under European data protection laws such as GDPR.

1. Immediately update all macOS systems to version Sequoia 15.5 or later, which contains the patch for this vulnerability. 2. Enforce strict application installation policies, limiting installations to trusted sources such as the Apple App Store and verified developers to reduce exposure to malicious apps. 3. Deploy endpoint detection and response (EDR) solutions capable of monitoring for sandbox escape behaviors and anomalous system calls indicative of quarantine bypass attempts. 4. Implement application whitelisting to restrict execution of unauthorized software. 5. Conduct regular audits of macOS devices to ensure compliance with patch management policies and detect any unauthorized modifications. 6. Educate users about the risks of installing untrusted software and encourage reporting of suspicious app behavior. 7. For organizations with high-security requirements, consider additional hardening measures such as disabling unnecessary services and using macOS security features like System Integrity Protection (SIP) and Mandatory Access Controls (MAC). 8. Monitor threat intelligence feeds for any emerging exploits targeting this vulnerability to enable rapid response.