CVE-2018-4151 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 11.3 is affected. macOS before 10.13.4 is affected. The issue involves the "iCloud Drive" component. A race condition allows attackers to execute arbitrary code in a privileged context via a crafted app.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 02/07/2021
The vulnerability identified as CVE-2018-4151 represents a critical race condition flaw within Apple's iCloud Drive component affecting multiple operating systems including iOS versions prior to 11.3 and macOS versions prior to 10.13.4. This vulnerability resides within the iCloud Drive functionality that enables users to synchronize files across their Apple devices, making it a significant concern for users who rely heavily on cloud-based file management and synchronization services. The race condition occurs during the processing of file operations within the iCloud Drive framework, creating a window where malicious actors can exploit temporal inconsistencies in the system's handling of file transfers and modifications.
The technical exploitation of this vulnerability stems from improper synchronization mechanisms within the iCloud Drive component that govern how files are processed and transferred between local storage and remote iCloud servers. When a malicious application attempts to manipulate files through the iCloud Drive API, the race condition allows for concurrent access to shared resources without proper locking mechanisms or access controls. This flaw specifically manifests when multiple processes or threads attempt to access the same file or directory structure simultaneously, creating opportunities for attackers to inject malicious code that executes with elevated privileges. The vulnerability is classified under CWE-362, which describes race conditions that can lead to security flaws when multiple threads or processes access shared resources concurrently without proper synchronization.
The operational impact of CVE-2018-4151 extends beyond simple privilege escalation as it provides attackers with the ability to execute arbitrary code within a privileged context, potentially enabling full system compromise. Attackers can craft malicious applications that exploit this race condition to gain unauthorized access to sensitive data, modify system files, or establish persistent backdoors within affected systems. The implications are particularly severe for enterprise environments where iCloud Drive synchronization is commonly used for document management and collaboration, as successful exploitation could lead to data breaches, unauthorized access to corporate information, and potential lateral movement within networked environments. This vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1068 for exploit for privilege escalation, demonstrating how attackers can leverage such flaws to gain deeper system access.
Mitigation strategies for CVE-2018-4151 primarily focus on updating affected systems to the patched versions of iOS 11.3 and macOS 10.13.4, which include proper synchronization mechanisms and access controls to prevent the race condition from being exploited. Organizations should implement comprehensive patch management procedures to ensure all affected devices are updated promptly, particularly those running older versions of Apple's operating systems. Additional protective measures include monitoring for suspicious iCloud Drive activity, implementing network segmentation to limit potential lateral movement, and conducting regular security assessments to identify systems that may still be vulnerable. Security teams should also consider deploying endpoint protection solutions that can detect anomalous behavior patterns associated with privilege escalation attempts and file manipulation activities within cloud synchronization components. The vulnerability serves as a reminder of the critical importance of proper synchronization mechanisms in multi-threaded environments and highlights the need for robust access control implementations in cloud-based services.