CVE-2021-31000 in macOS
Summary
by MITRE • 08/25/2021
A permissions issue was addressed with improved validation. This issue is fixed in iOS 15.2 and iPadOS 15.2, watchOS 8.3, macOS Monterey 12.1, tvOS 15.2. A malicious application may be able to read sensitive contact information.
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Analysis
by VulDB Data Team • 11/22/2023
The vulnerability identified as CVE-2021-31000 represents a critical permissions flaw within Apple's operating systems that allows malicious applications to access sensitive contact information without proper authorization. This issue stems from inadequate validation mechanisms that should have prevented unauthorized data access. The vulnerability affects multiple Apple platforms including iOS 15.2 and iPadOS 15.2, watchOS 8.3, macOS Monterey 12.1, and tvOS 15.2, indicating a systemic weakness in the permission architecture across Apple's ecosystem. The flaw falls under the category of improper access control as defined by CWE-284, where applications fail to properly validate their access rights to protected resources. The security implications are particularly severe given that contact information often contains personally identifiable information that can be exploited for identity theft, social engineering attacks, and other malicious activities. This vulnerability represents a direct violation of the principle of least privilege, where applications should only have access to the data necessary for their legitimate operation.
The technical implementation of this flaw involves a weakness in the permission validation system that governs how applications interact with the contacts database. When an application attempts to access contact information, the system should verify that the application has proper authorization and that the access request aligns with the application's declared permissions. However, this validation process contained a gap that allowed malicious applications to bypass these checks and directly read sensitive contact data. The flaw likely manifests through improper sandboxing mechanisms or inadequate input validation in the system calls that handle contact data access. This type of vulnerability is particularly dangerous because it operates at a system level where applications can potentially access data that should be restricted to specific, legitimate use cases. The issue demonstrates a failure in the application security model where the operating system's permission enforcement mechanisms were insufficient to prevent unauthorized access to sensitive user data.
The operational impact of CVE-2021-31000 extends beyond simple data exposure, as it creates a persistent threat vector for attackers who can leverage this weakness to build sophisticated reconnaissance campaigns. Malicious actors could use this vulnerability to harvest contact lists from affected devices, potentially enabling large-scale social engineering operations or targeted phishing attacks. The vulnerability's presence across multiple Apple platforms means that attackers can potentially target users across different devices and operating environments, increasing the attack surface and potential damage. This flaw creates opportunities for attackers to gather intelligence about user relationships, business contacts, and personal connections that can be used for various malicious purposes including financial fraud, identity theft, and corporate espionage. The vulnerability's exploitation requires minimal privileges and can be automated, making it particularly dangerous for widespread deployment. Organizations and individuals should consider this vulnerability as a potential indicator of broader security weaknesses in their mobile device management and application security practices.
The remediation for CVE-2021-31000 involves updating affected systems to the patched versions mentioned in the advisory, which include iOS 15.2, iPadOS 15.2, watchOS 8.3, macOS Monterey 12.1, and tvOS 15.2. These updates implement improved validation mechanisms that properly enforce access controls for contact information. System administrators should prioritize these updates across all affected devices, particularly in enterprise environments where mobile devices contain sensitive organizational data. The patch addresses the underlying permission validation flaw by strengthening the sandboxing mechanisms and implementing more rigorous access control checks. Organizations should also conduct comprehensive security assessments to identify any potential exploitation attempts that may have occurred before the patch was applied. The vulnerability's resolution aligns with the ATT&CK framework's mitigation strategies for privilege escalation and credential access, specifically addressing techniques related to unauthorized access to sensitive data. Security teams should monitor for any suspicious application behavior or unexpected data access patterns that might indicate exploitation attempts, as the vulnerability represents a significant risk to user privacy and organizational security. The fix demonstrates Apple's commitment to addressing access control vulnerabilities through systematic updates that strengthen the overall security posture of their platforms.