CVE-2023-42831 is a medium-severity vulnerability affecting Apple macOS and related operating systems including iOS and iPadOS. The vulnerability allows an application to fingerprint the user, which means the app can collect unique device or user-specific information that can be used to track or identify the user across sessions or services. This fingerprinting capability arises from a flaw in the system code that was subsequently removed in patched versions of macOS Big Sur (11.7.9), macOS Monterey (12.6.8), macOS Ventura (13.5), iOS 15.7.8, and iPadOS 15.7.8. The vulnerability does not require privileges (PR:N) but does require user interaction (UI:R), such as running the app or granting it some level of access. The attack vector is local (AV:L), meaning the attacker must have local access to the device to exploit this issue. The vulnerability impacts confidentiality (C:H) by potentially exposing user-identifying information but does not affect integrity or availability. There are no known exploits in the wild at this time. The vulnerability was addressed by removing the vulnerable code, indicating a code-level fix rather than a configuration change. The CVSS score of 5.5 reflects a moderate risk primarily due to the local attack vector and the requirement for user interaction, limiting the ease of exploitation. However, the ability to fingerprint users can have privacy implications and may facilitate further targeted attacks or tracking.

For European organizations, this vulnerability primarily poses a privacy risk rather than a direct operational threat. The ability for an app to fingerprint users could lead to unauthorized tracking or profiling of employees or customers, potentially violating GDPR and other privacy regulations prevalent in Europe. Organizations handling sensitive user data or operating in privacy-sensitive sectors (e.g., finance, healthcare, government) may face reputational damage or regulatory scrutiny if user fingerprinting leads to data misuse or breaches of privacy policies. Although the vulnerability does not directly compromise system integrity or availability, the exposure of unique user identifiers could be leveraged in multi-stage attacks or social engineering campaigns. The requirement for local access and user interaction somewhat limits the threat scope, but insider threats or malicious apps installed by users could exploit this vulnerability. Overall, the impact is moderate but significant in contexts where user privacy is critical.

European organizations should ensure all Apple devices are updated promptly to the fixed versions: macOS Big Sur 11.7.9, macOS Monterey 12.6.8, macOS Ventura 13.5, iOS 15.7.8, and iPadOS 15.7.8 or later. Beyond patching, organizations should enforce strict application control policies to prevent unauthorized or untrusted apps from running, especially those sourced outside official app stores. Implement endpoint security solutions capable of detecting suspicious local app behaviors that attempt to access device fingerprinting APIs or gather unique device identifiers. User education is critical to reduce the risk of social engineering that could lead to installation of malicious apps. Additionally, organizations should audit and monitor privacy settings on Apple devices to limit app permissions that could facilitate fingerprinting. For highly sensitive environments, consider deploying mobile device management (MDM) solutions that enforce security baselines and restrict app installation. Regular privacy impact assessments should be conducted to ensure compliance with GDPR and other relevant regulations in light of this vulnerability.