CVE-2015-1308 in kde-workspace
Summary
by MITRE
kde-workspace 4.2.0 and plasma-workspace before 5.1.95 allows remote attackers to obtain input events, and consequently obtain passwords, by leveraging access to the X server when the screen is locked.
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Analysis
by VulDB Data Team • 03/04/2025
The vulnerability identified as CVE-2015-1308 affects the kde-workspace and plasma-workspace components of the KDE desktop environment, specifically versions prior to 5.1.95. This security flaw represents a critical issue in the handling of input events when the graphical user interface is locked, creating a significant attack surface that can be exploited by remote adversaries. The vulnerability stems from the improper management of X server access during screen locking procedures, allowing malicious actors to intercept and capture sensitive input data including passwords and other confidential information.
The technical root cause of this vulnerability lies in the insufficient access controls and event handling mechanisms within the X server interaction layers of the KDE desktop environment. When a user locks their screen, the system should properly isolate input events and prevent unauthorized access to the graphical session. However, the flaw allows remote attackers to establish connections to the X server and capture input events that occur while the screen is locked. This occurs because the locking mechanism fails to properly restrict access to input events, enabling attackers to monitor and record keystrokes, mouse movements, and other user interactions even when the display is secured. The vulnerability specifically targets the X11 protocol implementation within KDE's workspace components, where the screen locking service does not adequately sanitize input event streams.
The operational impact of CVE-2015-1308 is severe and multifaceted, particularly in environments where remote access is possible or where attackers can establish network connections to systems running vulnerable KDE versions. Attackers can leverage this vulnerability to perform credential theft attacks, capturing passwords, PINs, and other sensitive authentication data entered by users while their screens are locked. This represents a direct violation of the principle of least privilege and undermines the fundamental security assumptions of graphical user interface locking mechanisms. The attack vector is particularly concerning because it requires only remote access to the X server, which may be accessible through various network protocols or local network connections, making it exploitable in both internal network environments and public-facing systems. This vulnerability essentially nullifies the security benefits of screen locking, transforming a protective mechanism into a vector for information disclosure.
The security implications of this vulnerability extend beyond simple password theft to encompass broader confidentiality and integrity concerns within the affected systems. According to CWE classification, this issue relates to CWE-200: "Information Exposure" and potentially CWE-284: "Improper Access Control" within the context of graphical session management. The vulnerability aligns with ATT&CK technique T1555.001: "Credentials from Password Stores" and T1074.001: "Data Staged" as attackers can capture credentials in transit or at rest within the graphical session context. Organizations running affected KDE versions face significant risk of credential compromise, particularly in shared office environments, public computing facilities, or any scenario where unauthorized network access to X server connections might occur. The vulnerability's impact is amplified in enterprise environments where users frequently lock their screens and may be vulnerable to attack while their systems remain accessible over the network.
Mitigation strategies for CVE-2015-1308 require immediate implementation of software updates to the latest available versions of KDE workspace components, specifically ensuring that plasma-workspace is updated to version 5.1.95 or later. Organizations should also implement network-level controls to restrict access to X server connections, particularly by disabling unnecessary X11 forwarding and implementing proper firewall rules to limit X server access to trusted network segments. Additional mitigations include enabling strong authentication mechanisms such as multi-factor authentication to reduce the impact of credential theft, implementing proper screen locking policies that ensure secure locking mechanisms, and conducting regular security assessments to identify and remediate similar vulnerabilities in graphical environments. System administrators should also consider implementing intrusion detection systems to monitor for suspicious X server access patterns and ensure that all users are educated about the risks of leaving systems unattended with locked screens. The vulnerability serves as a reminder of the importance of proper input event handling in graphical environments and the critical need for secure session management in desktop computing environments.