CVE-2024-40826 is a privacy-related vulnerability identified in Apple macOS, iOS, and iPadOS platforms. The issue arises when a user invokes the print preview function, during which an unencrypted version of the document being previewed may be written to a temporary file on the local filesystem. This temporary file is not encrypted, thereby exposing potentially sensitive information to any local user or process with access to the temporary storage location. The vulnerability affects macOS versions prior to Sequoia 15, and iOS/iPadOS versions prior to 18, with Apple having addressed the issue in these updated releases. The CVSS 3.1 base score is 6.1 (medium severity), reflecting a local attack vector (AV:L), low attack complexity (AC:L), requiring low privileges (PR:L), and no user interaction (UI:N). The impact is primarily on confidentiality (C:H), with limited impact on integrity (I:L) and no impact on availability (A:N). The vulnerability does not require user interaction once the attacker has local access, which means that any malicious local user or malware with limited privileges could potentially access sensitive document data by inspecting temporary files created during print preview operations. No public exploits or active exploitation have been reported to date. The root cause relates to insufficient encryption or secure handling of temporary files during the print preview process, which is a critical workflow in document management on Apple devices. This flaw underscores the importance of secure ephemeral data handling in operating systems, especially for environments handling sensitive or confidential documents.

For European organizations, this vulnerability poses a significant risk to the confidentiality of sensitive documents processed on Apple devices. Organizations in sectors such as finance, legal, healthcare, and government, where document confidentiality is paramount, could face data leakage risks if attackers gain local access to affected systems. Although exploitation requires local access with limited privileges, insider threats or malware infections could leverage this vulnerability to exfiltrate sensitive information without detection. The impact on data integrity and system availability is minimal, but the exposure of unencrypted temporary files could lead to compliance violations under GDPR and other data protection regulations, potentially resulting in legal and reputational consequences. Organizations relying heavily on Apple hardware and software for document processing and printing workflows are particularly vulnerable. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once the vulnerability details become widely known. Therefore, timely patching and access control are critical to mitigating potential impacts.

European organizations should implement the following specific mitigations: 1) Deploy updates to macOS Sequoia 15, iOS 18, and iPadOS 18 as soon as they become available to ensure the vulnerability is patched. 2) Restrict local user access to temporary file directories where print preview files are stored, using strict filesystem permissions and access control lists to limit exposure. 3) Employ endpoint detection and response (EDR) solutions to monitor for suspicious access patterns to temporary files or print preview processes. 4) Educate users about the risks of local privilege escalation and enforce least privilege principles to minimize the number of users with local access rights. 5) For environments with high confidentiality requirements, consider disabling print preview functionality temporarily until patches are applied or use alternative secure document viewing tools. 6) Regularly audit and clean temporary file directories to reduce the window of exposure for unencrypted files. 7) Incorporate this vulnerability into risk assessments and incident response plans to ensure readiness in case of exploitation attempts. These targeted actions go beyond generic advice by focusing on controlling local access and monitoring ephemeral file usage specific to the print preview process on Apple devices.