CVE-2014-3203 in Unity
Summary
by MITRE
Unity before 7.2.1, as used in Ubuntu 14.04, does not properly restrict access to the Dash when the lock screen is active, which allows physically proximate attackers to bypass the lock screen and execute arbitrary commands, as demonstrated by pressing the SUPER key before the screen auto-locks.
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Analysis
by VulDB Data Team • 03/21/2022
The vulnerability identified as CVE-2014-3203 affects Unity desktop environment versions prior to 7.2.1, specifically impacting Ubuntu 14.04 systems where the lock screen functionality fails to properly restrict access to the Dash interface. This security flaw represents a critical authorization bypass issue that undermines the fundamental security posture of the desktop environment. The vulnerability stems from improper access control mechanisms within the Unity shell implementation, creating a window of opportunity for attackers to exploit the system's lock screen protection. The flaw manifests when the lock screen is active but the Dash remains accessible, allowing unauthorized interaction with the system interface.
The technical implementation of this vulnerability involves a failure in the desktop environment's session management and access control policies. When the system enters lock mode, normal user interface restrictions should prevent access to system controls and applications, but Unity's implementation allows the Dash to remain accessible through the SUPER key press. This design flaw creates a race condition where physical proximity to the device enables attackers to immediately access system functionality before the screen locks completely. The vulnerability specifically targets the interaction between the lock screen state management and the Dash activation mechanism, where the system fails to properly enforce session restrictions during the transition period.
From an operational perspective, this vulnerability presents a significant risk to physical security and system integrity. Attackers with physical access to a locked system can bypass the lock screen protection by simply pressing the SUPER key, which immediately opens the Dash interface and provides access to applications, system settings, and potentially sensitive data. This type of attack falls under the category of local privilege escalation and unauthorized access, as it allows attackers to execute arbitrary commands without proper authentication. The impact extends beyond simple data exposure to potential system compromise, as access to the Dash interface provides pathways to system utilities and applications that could be leveraged for further exploitation.
The vulnerability aligns with CWE-284, which addresses improper access control in software systems, and demonstrates how desktop environment security can be compromised through inadequate session management. From an adversarial perspective, this flaw maps to ATT&CK technique T1547.001, which involves the abuse of system services and privileges. The attack vector is particularly concerning as it requires minimal technical expertise and can be executed by anyone with physical proximity to the target system, making it a high-risk vulnerability in environments where unauthorized physical access is possible. Organizations should consider this vulnerability as part of their broader security posture assessment, particularly in environments where sensitive data processing occurs.
Mitigation strategies should include immediate deployment of the Unity 7.2.1 update or later versions that properly address the access control flaw. System administrators should also implement additional physical security measures such as device encryption, automatic screen locking with shorter timeouts, and monitoring for unauthorized access attempts. The vulnerability highlights the importance of proper session management in desktop environments and underscores the need for comprehensive security testing of user interface components. Organizations should conduct security assessments to identify similar access control issues in other desktop environments and implement robust access control policies that properly enforce system state restrictions during authentication and session management phases.