CVE-2023-42896 is a vulnerability in Apple iOS, iPadOS, and macOS operating systems that allows an application to modify protected parts of the file system due to improper handling of temporary files. This flaw stems from insufficient validation or control over temporary file operations, which can be exploited by a malicious or compromised app to alter system files or other protected data areas that should normally be inaccessible. The vulnerability affects multiple Apple OS versions, including iOS 16.7.3, 17.2, iPadOS 16.7.3, 17.2, and macOS Monterey 12.7.2, Ventura 13.6.3, and Sonoma 14.2. The CVSS v3.1 score is 5.5 (medium), with the vector indicating local attack vector (AV:L), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), unchanged scope (S:U), no confidentiality impact (C:N), high integrity impact (I:H), and no availability impact (A:N). This means an attacker must have local access and trick a user into interacting with the malicious app to exploit the vulnerability. The primary impact is on system integrity, as unauthorized modifications to protected file system areas can undermine system stability, trust, and potentially enable further attacks or persistence mechanisms. Apple addressed the issue by improving the handling of temporary files in the affected OS versions. There are no known exploits in the wild at the time of publication, but the vulnerability poses a risk if exploited in targeted attacks or malware campaigns.

For European organizations, this vulnerability could lead to unauthorized modification of critical system files on Apple devices, potentially compromising the integrity of enterprise-managed mobile and desktop environments. This can undermine trust in device security, enable persistence of malicious code, or facilitate privilege escalation chains when combined with other vulnerabilities. Although confidentiality and availability are not directly impacted, the integrity breach can disrupt security controls, compliance postures, and forensic investigations. Organizations relying heavily on Apple ecosystems for sensitive communications, data processing, or operational technology may face increased risk of targeted attacks exploiting this flaw. The requirement for user interaction and local access somewhat limits remote exploitation, but social engineering or insider threats could still leverage this vulnerability. Failure to patch promptly could expose European enterprises to advanced persistent threats or malware that abuse this vulnerability to maintain footholds or manipulate system behavior.

European organizations should immediately deploy the security updates released by Apple for iOS 16.7.3, 17.2, iPadOS 16.7.3, 17.2, and macOS Monterey 12.7.2, Ventura 13.6.3, and Sonoma 14.2 to remediate this vulnerability. Beyond patching, organizations should enforce strict app installation policies, limiting devices to trusted and vetted applications from the official Apple App Store to reduce the risk of malicious apps exploiting this flaw. Implement mobile device management (MDM) solutions to monitor and control app permissions and behavior, especially regarding file system access. Educate users about the risks of interacting with untrusted apps or links that could trigger exploitation. Conduct regular audits of device integrity and file system changes to detect unauthorized modifications early. Employ endpoint detection and response (EDR) tools capable of identifying suspicious local file system activity. Finally, maintain robust incident response plans tailored to Apple device environments to quickly contain and remediate any exploitation attempts.