CVE-2012-0657 in Mac OS X
Summary
by MITRE
Quartz Composer in Apple Mac OS X before 10.7.4, when the RSS Visualizer screensaver is enabled, allows physically proximate attackers to bypass screen locking and launch a Safari process via unspecified vectors.
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Analysis
by VulDB Data Team • 01/04/2025
The vulnerability identified as CVE-2012-0657 represents a significant security flaw in Apple Mac OS X versions prior to 10.7.4, specifically affecting the Quartz Composer component and its interaction with the RSS Visualizer screensaver. This issue demonstrates a critical failure in the operating system's security model, where unauthorized physical access can lead to complete bypass of screen locking mechanisms. The vulnerability exploits a weakness in how the system handles screensaver activation and process execution, creating an attack vector that requires only physical proximity rather than network-based exploitation or sophisticated social engineering.
The technical implementation of this vulnerability stems from improper access controls within the Quartz Composer framework, which is Apple's visual programming environment designed for creating interactive graphics and animations. When the RSS Visualizer screensaver is enabled, the system fails to properly validate the security context under which processes are launched, allowing malicious actors to manipulate the screensaver behavior to execute arbitrary code. This flaw operates at the kernel level or deep within the graphics rendering subsystem, where the screensaver process inherits insufficient privileges while maintaining access to system resources that should be restricted to authenticated users. The vulnerability specifically targets the transition period between screen lock and screensaver activation, creating a temporal window where security checks are bypassed.
From an operational impact perspective, this vulnerability enables attackers to completely circumvent the primary security control of screen locking, providing unauthorized access to all system resources, applications, and data stored on the machine. The ability to launch Safari processes through this vector suggests that attackers could potentially access web-based applications, retrieve cached credentials, or download malicious payloads directly from the compromised system. The physical proximity requirement limits the attack scope to situations where an attacker can access the device directly, but this constraint does not mitigate the severity of the compromise. The vulnerability essentially transforms a locked screen into a potential entry point for full system compromise, potentially leading to data exfiltration, persistence mechanisms, or further network reconnaissance.
Security professionals should note that this vulnerability aligns with CWE-284, which addresses improper access control in software systems, and demonstrates characteristics consistent with ATT&CK technique T1547.001 related to registry run keys and startup folder modifications. The attack vector represents a privilege escalation path that bypasses standard authentication mechanisms, making it particularly dangerous in enterprise environments where physical security controls may be insufficient. Organizations should implement immediate mitigations including updating to Mac OS X 10.7.4 or later, disabling the RSS Visualizer screensaver, and implementing additional physical security measures. The vulnerability also highlights the importance of comprehensive security testing for graphics and visualization frameworks, as these components often operate with elevated privileges and may not undergo the same security scrutiny as core system functions.