CVE-2021-30750 in macOS
Summary
by MITRE • 09/08/2021
The issue was addressed with improved permissions logic. This issue is fixed in macOS Big Sur 11.3. A malicious application may be able to access the user's recent contacts.
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Analysis
by VulDB Data Team • 09/11/2021
The vulnerability identified as CVE-2021-30750 represents a significant permission escalation flaw within macOS Big Sur operating systems prior to version 11.3. This issue stems from inadequate access controls that allowed malicious applications to bypass normal security boundaries and gain unauthorized access to user contact data. The vulnerability demonstrates a critical weakness in the operating system's permission model where proper isolation between applications was not maintained, creating an avenue for unauthorized data access.
The technical flaw manifests through improper validation of application permissions within the macOS security framework. Specifically, the vulnerability occurs when applications attempt to access the user's recent contacts database without proper authorization checks. This flaw falls under the category of improper access control as defined by CWE-284, where an attacker can access resources without appropriate authorization. The vulnerability exploits the lack of robust permission validation mechanisms that should normally prevent one application from accessing another application's data or user information.
The operational impact of this vulnerability extends beyond simple data exposure, as contact information represents highly sensitive personal data that can be leveraged for social engineering attacks, identity theft, or targeted phishing campaigns. An attacker with malicious software installed on a user's system could systematically harvest contact information to build comprehensive profiles of users' social networks and professional connections. This represents a significant privacy breach that could enable sophisticated attack campaigns targeting individuals based on their relationship networks. The vulnerability affects the fundamental security principle of least privilege, where applications should only have access to resources necessary for their operation.
Mitigation strategies for CVE-2021-30750 involve immediate deployment of macOS Big Sur 11.3 updates which address the underlying permission logic flaws through enhanced access control mechanisms. System administrators should also implement additional monitoring for unauthorized application behavior and maintain strict application vetting processes before deployment. The fix implemented by Apple demonstrates proper remediation through strengthened permission validation that ensures applications cannot access user contact data without explicit user consent and proper authorization tokens. Organizations should also consider implementing endpoint detection and response solutions to monitor for suspicious application behavior patterns that might indicate exploitation attempts. This vulnerability highlights the importance of maintaining up-to-date security patches and following the principle of defense in depth to protect against such permission-related security flaws. The resolution aligns with recommended practices from the cybersecurity community for addressing access control vulnerabilities and maintaining system integrity through proper software maintenance and security updates.