CVE-2014-4372 in iOS
Summary
by MITRE
syslogd in the syslog subsystem in Apple iOS before 8 and Apple TV before 7 allows local users to change the permissions of arbitrary files via a symlink attack on an unspecified file.
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Analysis
by VulDB Data Team • 02/20/2022
The vulnerability identified as CVE-2014-4372 represents a significant privilege escalation flaw within Apple's iOS and Apple TV operating systems. This issue affects versions prior to iOS 8 and Apple TV software version 7, where the syslogd daemon in the syslog subsystem exhibits improper handling of file permissions during symlink resolution. The vulnerability stems from a lack of proper validation when processing symbolic links, creating an opportunity for local attackers to manipulate file permissions through carefully crafted symlink attacks. This weakness falls under the category of insufficient verification of data received from untrusted sources, which is classified as CWE-20 by the CWE standard.
The technical implementation of this vulnerability occurs within the syslogd daemon's file handling mechanisms where it fails to properly verify the target of symbolic links before performing permission modifications. When a local user creates a malicious symlink pointing to a target file, the syslogd process follows the symlink and modifies permissions on the target file rather than the intended symlink itself. This behavior enables attackers to escalate their privileges by targeting critical system files or directories that are accessible through the syslog subsystem. The attack vector specifically leverages the principle of least privilege violation, where the syslogd process operates with elevated permissions but fails to validate the integrity of the files it processes.
The operational impact of CVE-2014-4372 extends beyond simple file permission modification, as it provides a pathway for local privilege escalation that could enable attackers to gain root-level access to affected devices. This vulnerability is particularly concerning in mobile environments where iOS devices and Apple TV systems handle sensitive user data and system configurations. Attackers could exploit this flaw to modify system binaries, install malicious software, or access restricted data by manipulating the permissions of critical system files. The vulnerability aligns with ATT&CK technique T1068 which describes the use of local privilege escalation techniques, and T1548.001 which covers abuse of system permissions. The attack requires local access but provides significant operational advantages to threat actors who can leverage this to establish persistent access or escalate their privileges within the device's security boundaries.
Mitigation strategies for CVE-2014-4372 focus primarily on updating affected systems to versions that address the underlying symlink handling flaw. Apple released iOS 8 and Apple TV software version 7 which contain patches that properly validate symlink targets before modifying file permissions. System administrators should prioritize deployment of these updates across all affected devices to eliminate the attack vector. Additional mitigations include implementing proper file system permissions, monitoring for suspicious symlink creation patterns, and maintaining comprehensive system logging to detect unauthorized permission modifications. The vulnerability demonstrates the importance of proper input validation and secure file handling practices, particularly in system daemons that operate with elevated privileges. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of local privilege escalation attacks, while ensuring that security patches are applied promptly to prevent exploitation of known vulnerabilities.