CVE-2003-0198 in Mac OS X
Summary
by MITRE
Mac OS X before 10.2.5 allows guest users to modify the permissions of the DropBox folder and read unauthorized files.
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Analysis
by VulDB Data Team • 04/14/2017
The vulnerability described in CVE-2003-0198 represents a significant access control flaw in Mac OS X versions prior to 10.2.5 that fundamentally undermines the security model of the operating system. This issue specifically targets the DropBox folder functionality, which serves as a shared directory where users can place files for others to access. The flaw allows guest users to manipulate the permissions of this directory and subsequently read files that should remain restricted to authorized users. This represents a classic privilege escalation vulnerability where unprivileged users can gain unauthorized access to sensitive data through manipulation of system directories. The vulnerability exists at the filesystem permission level and demonstrates poor implementation of access control mechanisms within the operating system's user management framework.
The technical implementation of this vulnerability stems from inadequate permission checking within the DropBox folder handling code. When guest users interact with the DropBox directory, the system fails to properly validate whether the requesting user has sufficient privileges to modify directory permissions or access files within it. This flaw can be exploited through various means including direct file system manipulation, symbolic link attacks, or by leveraging the system's built-in sharing mechanisms. The vulnerability specifically affects the permission model implementation where the system does not properly enforce the distinction between guest and authenticated user privileges when accessing shared directories. This type of flaw aligns with CWE-284 which describes improper access control, and represents a failure in the principle of least privilege enforcement. The vulnerability operates at the kernel level in some implementations, making it particularly dangerous as it can bypass user-space security controls.
The operational impact of this vulnerability extends beyond simple unauthorized file access, creating potential for data leakage, information disclosure, and system compromise. Guest users who can modify DropBox permissions can effectively create backdoors or establish persistent access points within the system. This vulnerability particularly affects environments where Mac OS X systems are used in shared or public computing scenarios where guest accounts are enabled. The ability to read unauthorized files means that sensitive information stored in user directories, system configuration files, or other restricted locations could be exposed to unauthorized parties. Attackers could leverage this vulnerability to gather intelligence about system configuration, user activities, or even extract credentials and other sensitive data. The vulnerability also creates potential for privilege escalation attacks where guest users can manipulate system directories to gain elevated access to the system. This type of vulnerability would be classified under ATT&CK technique T1078 which covers valid accounts and T1566 which covers credential harvesting, as attackers could use this to access files they should not normally be able to read.
Mitigation strategies for this vulnerability require immediate system updates to Mac OS X 10.2.5 or later versions where the permission handling has been corrected. System administrators should disable guest access where possible or implement additional security controls around shared directories. The vulnerability can be addressed through proper system hardening including disabling unnecessary sharing features, implementing robust access controls, and monitoring for unauthorized permission changes. Organizations should also implement regular security audits to identify similar permission-related issues in other system components. Additional mitigations include implementing file integrity monitoring solutions that can detect unauthorized changes to critical directories and establishing proper logging of access attempts to shared resources. The fix implemented in Mac OS X 10.2.5 addresses the core permission checking logic and ensures that guest users cannot modify directory permissions or access files outside their authorized scope. This vulnerability highlights the importance of proper access control implementation and demonstrates how seemingly minor flaws in permission handling can create significant security risks in operating system implementations.