CVE-2016-2312 in plasma-workspace
Summary
by MITRE
Turning all screens off in Plasma-workspace and kscreenlocker while the lock screen is shown can result in the screen being unlocked when turning a screen on again.
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Analysis
by VulDB Data Team • 10/11/2024
The vulnerability described in CVE-2016-2312 affects the KDE Plasma workspace environment and specifically impacts the kscreenlocker component responsible for managing screen locking and unlocking operations. This issue represents a security flaw in the desktop environment's handling of screen state transitions, where the system fails to properly maintain the locked state during screen power management operations. The vulnerability occurs within the context of the X Window System and desktop session management, where screen power states are manipulated through standard power management interfaces.
The technical flaw manifests when users perform operations that turn all screens off while the lock screen is actively displayed. During this process, the kscreenlocker component does not properly maintain the authentication state and screen lock status. When screens are subsequently turned back on, the system incorrectly assumes that the screen should be unlocked, even though the user had explicitly locked the session. This behavior stems from improper state management within the screen locking subsystem, where the lock screen state is not correctly preserved during screen power transitions. The vulnerability is classified under CWE-284 Access Control, specifically related to improper privileges and state management in graphical user interfaces.
The operational impact of this vulnerability is significant within environments where users frequently manage screen power states or where automated power management is employed. An attacker could exploit this weakness by triggering screen power transitions while a user is away from their workstation, potentially gaining unauthorized access to the system when screens are reactivated. This represents a privilege escalation vector where the system's security controls are bypassed through legitimate power management operations. The vulnerability affects desktop environments running KDE Plasma 5.0 through 5.6, where the screen locking mechanism was not properly handling screen state changes during power management events.
Mitigation strategies for this vulnerability involve applying the vendor-provided security patches that address the screen state management issue within kscreenlocker. System administrators should ensure that all KDE Plasma desktop environments are updated to versions that contain the corrected screen locking behavior. Additionally, organizations should consider implementing supplementary security controls such as automatic screen locking after periods of inactivity, disabling screen power management during active sessions, and monitoring for unauthorized screen state changes. The vulnerability aligns with ATT&CK technique T1547.001 Account Policy Modification, as it involves bypassing legitimate authentication mechanisms through improper system state handling, and T1070.004 Indicator Removal on Host, since the system's security state is not properly maintained during transitions. Organizations should also consider implementing logging and monitoring solutions that can detect anomalous screen power management events that might indicate exploitation attempts.