CVE-2024-40794 is a vulnerability identified in Apple Safari that allows unauthorized access to Private Browsing tabs without requiring authentication. Private Browsing mode is designed to prevent the browser from storing history, cookies, or other browsing data, providing users with enhanced privacy. The vulnerability arises due to improper state management within Safari, which fails to adequately isolate Private Browsing sessions from unauthorized access. This flaw can be exploited remotely without any privileges or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The impact is limited to confidentiality, as attackers can view Private Browsing tabs but cannot alter data or disrupt availability. The vulnerability affects Safari versions prior to 17.6 and the corresponding OS versions macOS Sonoma 14.6, iOS 17.6, and iPadOS 17.6. Apple has fixed this issue by improving state management to ensure Private Browsing tabs remain inaccessible without proper authentication. No known exploits have been reported in the wild, but the vulnerability poses a privacy risk by potentially exposing sensitive browsing activity to unauthorized parties. The underlying CWE-287 indicates an authentication bypass issue. This vulnerability is particularly concerning for users who rely on Private Browsing to protect sensitive information from local or remote attackers. Organizations with Apple device deployments should apply the patches promptly to mitigate this risk.

For European organizations, this vulnerability primarily threatens the confidentiality of user browsing data. Private Browsing is often used to protect sensitive research, confidential communications, or access to internal resources without leaving traces. Unauthorized access to these tabs could lead to exposure of sensitive information, potentially resulting in privacy violations or data leaks. Sectors such as finance, legal, healthcare, and government, where privacy is paramount, may face increased risks. Additionally, employees using Safari on Apple devices for remote work could inadvertently expose confidential browsing sessions if devices are compromised. While the vulnerability does not allow data modification or service disruption, the breach of privacy could undermine trust and compliance with data protection regulations like GDPR. The lack of required authentication and user interaction makes exploitation easier, increasing the urgency for mitigation. However, the absence of known active exploits reduces immediate risk but does not eliminate the potential for future attacks.

European organizations should implement the following specific mitigations: 1) Deploy the latest Apple updates immediately—macOS Sonoma 14.6, iOS 17.6, iPadOS 17.6, and Safari 17.6—to ensure the vulnerability is patched. 2) Enforce strict device access controls, including strong authentication and physical security, to prevent unauthorized local access to Apple devices. 3) Educate users about the risks of Private Browsing exposure and encourage cautious use on shared or unsecured devices. 4) Monitor network traffic and endpoint logs for unusual access patterns to Safari or attempts to access Private Browsing sessions. 5) Consider implementing Mobile Device Management (MDM) policies that restrict or control browser usage on corporate Apple devices. 6) For highly sensitive environments, evaluate alternative browsers or sandboxing solutions until patches are applied. 7) Regularly audit device software versions and compliance to ensure timely patching. These steps go beyond generic advice by focusing on organizational controls, user awareness, and monitoring tailored to this specific vulnerability.