CVE-2015-7071 in Mac OS X
Summary
by MITRE
The File Bookmark component in Apple OS X before 10.11.2 allows attackers to bypass a sandbox protection mechanism for app scoped bookmarks via a crafted pathname.
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Analysis
by VulDB Data Team • 06/29/2022
The vulnerability identified as CVE-2015-7071 represents a significant sandbox bypass issue within Apple's operating system ecosystem, specifically affecting versions prior to macOS 10.11.2. This flaw resides in the File Bookmark component, which serves as a critical mechanism for maintaining file access permissions and security boundaries within the sandboxed application environment. The vulnerability exploits a design weakness in how the system handles app-scoped bookmarks, allowing malicious actors to circumvent the intended security controls that protect user data and system integrity. The issue demonstrates the complexity of sandbox implementations where seemingly minor flaws can lead to substantial security implications, particularly when dealing with file system access controls and user privacy boundaries.
The technical exploitation of this vulnerability occurs through the manipulation of crafted pathnames that exploit weaknesses in the bookmark resolution process. When applications attempt to resolve file bookmarks, the system fails to properly validate the pathname components, enabling attackers to construct malicious paths that bypass the sandbox restrictions. This particular flaw falls under the CWE-22 category of "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')" and aligns with ATT&CK technique T1197 for "Proxy Execution' and T1059 for 'Command and Scripting Interpreter' as attackers can leverage this bypass to execute unauthorized operations. The vulnerability essentially allows an attacker to escalate privileges by creating a malicious bookmark that points to restricted system locations, effectively undermining the fundamental security model that separates application processes from system resources.
The operational impact of CVE-2015-7071 extends beyond simple unauthorized file access, as it represents a critical failure in the sandboxing architecture that protects user data and system integrity. Applications that rely on bookmarks for file access can be exploited to gain access to files outside their designated scope, potentially leading to data exfiltration, system compromise, or privilege escalation attacks. This vulnerability particularly affects applications that handle user data, file management, or system integration, as the bypass allows attackers to access sensitive information that should remain protected by the sandbox mechanism. The implications are severe because the sandbox protection is designed to prevent applications from accessing unauthorized files, and this bypass undermines the entire security boundary that protects against such unauthorized access patterns.
Mitigation strategies for CVE-2015-7071 primarily involve updating to macOS 10.11.2 or later versions where Apple has implemented proper pathname validation and bookmark resolution mechanisms. System administrators should prioritize patching affected systems and monitor for any unauthorized access patterns that might indicate exploitation attempts. Organizations should also implement additional security controls such as monitoring file access patterns, implementing strict application whitelisting policies, and conducting regular security assessments of sandboxed applications. The vulnerability highlights the importance of proper input validation and secure coding practices in system-level components, particularly those handling file system operations and access controls. Security teams should also consider implementing network-based intrusion detection systems to monitor for suspicious bookmark-related activities that might indicate exploitation attempts. Given the nature of the vulnerability and its potential for privilege escalation, organizations should conduct thorough risk assessments to determine the impact on their specific environments and implement layered security approaches to protect against similar vulnerabilities in other system components.