CVE-2024-27840 is a vulnerability in Apple’s operating systems including iOS, iPadOS, macOS, tvOS, visionOS, and watchOS that allows an attacker who has already obtained kernel code execution privileges to bypass kernel memory protections. The vulnerability is due to improper memory handling within the kernel, specifically categorized under CWE-786 (Access of Memory Location Before Start of Buffer). This flaw could enable an attacker to circumvent security mechanisms designed to protect kernel memory, potentially allowing further escalation of privileges, persistence, or evasion of detection mechanisms. The vulnerability affects multiple Apple platforms and versions prior to the patched releases: iOS 16.7.8, iOS 17.5, macOS Monterey 12.7.5, macOS Ventura 13.6.7, tvOS 17.5, visionOS 1.2, and watchOS 10.5. The CVSS v3.1 base score is 7.5, indicating high severity, with the vector reflecting that exploitation requires local access (AV:L), high complexity (AC:H), high privileges (PR:H), no user interaction (UI:N), and scope change (S:C) with high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). While no public exploits are known, the vulnerability poses a significant risk if an attacker already has kernel-level code execution, as it can be leveraged to bypass critical kernel memory protections and further compromise the system. Apple fixed the issue by improving memory handling in the kernel to prevent such bypasses.

The primary impact of CVE-2024-27840 is on the confidentiality, integrity, and availability of Apple devices’ kernel memory. An attacker with existing kernel code execution could exploit this vulnerability to bypass kernel memory protections, potentially leading to full system compromise, including unauthorized access to sensitive data, persistent malware installation, and evasion of security controls. This could affect a wide range of Apple devices used globally, including iPhones, iPads, Macs, Apple TVs, Apple Watches, and devices running visionOS. Organizations relying on Apple platforms for critical operations, especially those in sectors like finance, government, healthcare, and technology, could face significant risks if attackers chain this vulnerability with other exploits. The requirement for prior kernel code execution limits the attack surface but also means this vulnerability could be used as a powerful post-exploitation tool to deepen control over compromised devices. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially from advanced persistent threat (APT) actors who may develop private exploits.

To mitigate CVE-2024-27840, organizations and users should promptly apply the security updates released by Apple for all affected platforms: iOS 16.7.8 and 17.5, iPadOS 16.7.8 and 17.5, macOS Monterey 12.7.5, macOS Ventura 13.6.7, tvOS 17.5, visionOS 1.2, and watchOS 10.5. Beyond patching, organizations should implement strict access controls to limit local privilege escalation opportunities, including enforcing least privilege principles and restricting physical and local access to devices. Employ endpoint detection and response (EDR) solutions capable of monitoring kernel-level activity to detect anomalous behavior indicative of kernel code execution. Regularly audit and monitor device integrity and kernel module loads. Network segmentation and limiting exposure of Apple devices to untrusted networks can reduce the likelihood of initial kernel code execution exploits. Additionally, organizations should maintain robust incident response plans to quickly contain and remediate any compromise involving kernel-level exploits. Avoid delaying updates, as attackers may develop exploits targeting this vulnerability over time.