CVE-2017-2390 in tvOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10.3 is affected. macOS before 10.12.4 is affected. tvOS before 10.2 is affected. watchOS before 3.2 is affected. The issue involves symlink mishandling in the "libarchive" component. It allows local users to change arbitrary directory permissions via unspecified vectors.
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Analysis
by VulDB Data Team • 10/31/2024
The vulnerability identified as CVE-2017-2390 represents a critical security flaw within Apple's software ecosystem affecting multiple operating systems including iOS, macOS, tvOS, and watchOS. This issue resides within the libarchive component, a widely used library for handling various archive formats such as tar, zip, and others. The vulnerability stems from improper handling of symbolic links during archive extraction processes, creating a pathway for malicious actors to exploit directory permission structures. The affected versions demonstrate a fundamental flaw in how the system processes symbolic links when decompressing archive files, allowing attackers to manipulate file system permissions in unintended ways.
The technical implementation of this vulnerability involves the libarchive library's inadequate validation of symbolic link targets during archive extraction operations. When processing archive files containing symbolic links, the system fails to properly verify the legitimacy of link destinations, potentially allowing attackers to create or modify symbolic links that point to directories outside the intended extraction scope. This misconfiguration enables local users to exploit the system's permission handling mechanisms, enabling them to modify arbitrary directory permissions through carefully crafted archive files. The unspecified vectors mentioned in the description indicate that the attack can be executed through various methods of archive manipulation, making the vulnerability particularly dangerous as it can be exploited through multiple attack surfaces.
The operational impact of CVE-2017-2390 extends beyond simple permission modification, as it provides attackers with potential escalation capabilities within the affected systems. Local users who can execute malicious archive files can leverage this vulnerability to gain unauthorized access to sensitive directories, potentially compromising system integrity and confidentiality. The vulnerability operates at the file system level, meaning that successful exploitation could allow attackers to modify system directories, install malicious software, or manipulate critical system files. This represents a significant concern for Apple's ecosystem, as the vulnerability affects multiple device types and operating system versions, creating widespread potential for exploitation across Apple's product portfolio. The issue aligns with CWE-59, which describes improper handling of symbolic links, and demonstrates how such weaknesses can be exploited to gain unauthorized system access.
Mitigation strategies for this vulnerability require immediate patching of affected systems through official Apple security updates. Users should promptly upgrade to iOS 10.3, macOS 10.12.4, tvOS 10.2, and watchOS 3.2 or later versions where the vulnerability has been addressed. System administrators should conduct thorough inventory checks to identify all affected devices and ensure proper update deployment across all endpoints. Additionally, organizations should implement monitoring procedures to detect suspicious archive extraction activities and maintain strict access controls to prevent unauthorized users from executing potentially malicious archive files. The vulnerability demonstrates the importance of proper input validation and secure file handling practices, particularly when dealing with archive and compression libraries. Security professionals should consider this issue when conducting risk assessments for Apple environments and ensure that proper security controls are in place to prevent exploitation of similar vulnerabilities in other software components. This vulnerability also highlights the necessity of following secure coding practices and implementing proper privilege separation during file system operations to prevent unauthorized permission modifications.