CVE-2016-4679 in watchOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10.1 is affected. macOS before 10.12.1 is affected. tvOS before 10.0.1 is affected. watchOS before 3.1 is affected. The issue involves the "libarchive" component, which allows remote attackers to write to arbitrary files via a crafted archive containing a symlink.
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Analysis
by VulDB Data Team • 09/28/2022
The vulnerability identified as CVE-2016-4679 represents a critical file system manipulation flaw within Apple's software ecosystem affecting multiple operating systems and devices. This security issue resides within the libarchive component, a widely used library for handling various archive formats including tar, zip, and others. The vulnerability specifically targets iOS versions prior to 10.1, macOS versions prior to 10.12.1, tvOS versions prior to 10.0.1, and watchOS versions prior to 3.1, indicating a broad impact across Apple's product portfolio. The flaw stems from inadequate validation of symbolic link entries within archive files, creating a path traversal scenario that enables malicious actors to manipulate file system contents beyond intended boundaries.
The technical exploitation of this vulnerability occurs when a malicious archive file contains carefully crafted symbolic link entries that point to arbitrary file system locations. When the affected libarchive component processes such archives, it fails to properly validate or sanitize the symlink targets, allowing attackers to create or overwrite files in locations where they would normally not have write permissions. This represents a classic path traversal vulnerability that aligns with CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory. The vulnerability's exploitation mechanism allows remote attackers to write to arbitrary files, potentially leading to privilege escalation or unauthorized file modifications on affected systems.
The operational impact of CVE-2016-4679 extends beyond simple file system manipulation, as it can be leveraged for more sophisticated attacks within the affected Apple ecosystem. Attackers could potentially exploit this vulnerability to overwrite critical system files, inject malicious code into legitimate applications, or manipulate system configurations. The remote nature of the attack means that adversaries could compromise devices through maliciously crafted archive files delivered via email attachments, web downloads, or other attack vectors. This vulnerability particularly threatens mobile and embedded systems where users may unknowingly download and process malicious archives, making it a significant concern for enterprise environments and individual users alike. The impact is further amplified by the widespread use of libarchive across Apple's platforms, creating multiple potential attack surfaces for threat actors.
Mitigation strategies for this vulnerability require immediate system updates and patches from Apple, as the primary solution involves upgrading to unaffected versions of the operating systems. Organizations should implement network-level controls to block suspicious archive file types and monitor for unusual file system activity patterns that might indicate exploitation attempts. Security teams should also conduct thorough vulnerability assessments to identify any systems that may be running older versions of affected software. The remediation process must include comprehensive testing to ensure that patch deployment does not introduce compatibility issues with existing applications or system configurations. Additionally, user education regarding the risks of downloading and processing untrusted archive files remains crucial, as social engineering aspects of this vulnerability can be exploited through phishing campaigns or malicious websites. The vulnerability's classification under the ATT&CK framework would likely involve techniques related to privilege escalation and execution through legitimate system tools, making it a significant concern for security operations centers implementing threat detection and response protocols.