CVE-2012-3718 in Mac OS X
Summary
by MITRE
Apple Mac OS X before 10.7.5 and 10.8.x before 10.8.2 allows local users to read passwords entered into Login Window (aka LoginWindow) or Screen Saver Unlock by installing an input method that intercepts keystrokes.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 12/14/2021
This vulnerability exists in Apple Mac OS X versions prior to 10.7.5 and 10.8.2, representing a critical security flaw in the operating system's authentication mechanisms. The issue stems from the improper handling of input methods within the Login Window and Screen Saver Unlock processes, which creates an exploitable condition where malicious input methods can intercept and capture user keystrokes. The vulnerability specifically affects the system's trust model for authentication interfaces, allowing local attackers to bypass normal security controls through legitimate system components.
The technical flaw manifests through the interaction between the LoginWindow process and the input method framework, where input methods are granted elevated privileges that should be restricted to system-level components only. When a user enters their password into the Login Window or Screen Saver Unlock interface, the system's input method architecture allows third-party or malicious input methods to register themselves with the authentication process. This creates a keystroke interception opportunity where the malicious input method can capture each keystroke as it is typed, effectively logging the user's password without their knowledge or consent. The vulnerability is particularly concerning because it operates at the system level and leverages legitimate system components to perform unauthorized data collection.
The operational impact of this vulnerability extends beyond simple password theft, as it represents a fundamental breach in the operating system's security model for authentication. Attackers can exploit this weakness by simply installing a malicious input method package, which then operates in the background during authentication processes. This allows for persistent credential harvesting across multiple authentication events, potentially compromising user accounts and system access. The vulnerability affects both the initial login process and screen saver unlock functionality, creating multiple attack vectors for unauthorized access. According to CWE-254, this represents a weakness in the security model where the system fails to properly restrict privileges for authentication components, making it particularly dangerous for enterprise environments where multiple users share systems.
Mitigation strategies for this vulnerability require immediate system updates to the patched versions of Mac OS X, specifically 10.7.5 and 10.8.2, which address the input method privilege escalation issue. Organizations should implement comprehensive patch management policies that prioritize security updates for authentication-related components. System administrators should also consider monitoring for unauthorized input method installations through configuration management tools and security auditing procedures. The remediation process must include verification that legitimate input methods are properly configured and that malicious ones have been removed from the system. From an ATT&CK framework perspective, this vulnerability maps to T1546.004 for input method packages and T1078 for valid accounts, as it allows attackers to leverage legitimate system components to gain unauthorized access to credentials. Additional defensive measures should include user education about the risks of installing untrusted input methods and implementing system integrity protection mechanisms to prevent unauthorized modifications to authentication components.