CVE-2009-3851 in Solaris
Summary
by MITRE
Trusted Extensions in Sun Solaris 10 interferes with the operation of the xscreensaver-demo command for the XScreenSaver application, which makes it easier for physically proximate attackers to access an unattended workstation for which the intended screen locking did not occur, related to the "restart daemon."
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Analysis
by VulDB Data Team • 02/10/2025
The vulnerability described in CVE-2009-3851 represents a significant security flaw within the Trusted Extensions framework of Sun Solaris 10 operating system. This issue specifically impacts the XScreenSaver application's functionality, creating a critical weakness in the system's desktop security mechanisms. The problem manifests when the xscreensaver-demo command fails to operate correctly due to interference from Trusted Extensions, which are designed to provide mandatory access control and security policies within the Solaris environment. The Trusted Extensions component, which implements security labels and access controls for multi-level security environments, inadvertently disrupts the normal operation of the screen saver demonstration functionality, creating a window of opportunity for unauthorized access.
The technical root cause of this vulnerability lies in the interaction between the Trusted Extensions security framework and the XScreenSaver daemon process. When the xscreensaver-demo command attempts to execute, it encounters interference from the Trusted Extensions system that manages security labels and access controls for X11 applications. This interference prevents the proper restart of the screen saver daemon, which is essential for maintaining the security state of the workstation. The vulnerability specifically relates to how the Trusted Extensions framework handles process restarts and security context management when XScreenSaver components attempt to reinitialize their operational state. This misconfiguration allows the screen saver to fail to properly lock the workstation, leaving the system exposed to unauthorized access.
The operational impact of this vulnerability is particularly concerning for environments that rely on automated screen locking to maintain security. Physically proximate attackers can exploit this weakness by simply waiting for an unattended workstation to fail to lock properly, thereby gaining access to potentially sensitive information and system resources. The vulnerability creates a direct path for privilege escalation and unauthorized access, as the screen locking mechanism that should protect against casual observation and unauthorized use fails to function correctly. This issue is especially problematic in multi-level security environments where Trusted Extensions are deployed to enforce strict access controls, as it undermines the fundamental security assumptions of the system. The vulnerability affects the integrity of the security model by allowing unauthorized access through a mechanism that should provide basic protection against physical proximity attacks.
Organizations should implement several mitigation strategies to address this vulnerability effectively. The primary recommendation involves disabling or carefully configuring the Trusted Extensions framework when screen locking functionality is critical for security. System administrators should consider temporarily suspending Trusted Extensions during periods when screen locking is most important, or alternatively, implementing alternative screen locking mechanisms that do not conflict with the Trusted Extensions framework. Additionally, organizations should conduct thorough testing of their security configurations to ensure that screen locking mechanisms function correctly in environments where Trusted Extensions are enabled. The mitigation approach should also include monitoring for unauthorized access attempts and implementing additional physical security controls for workstations where this vulnerability exists. This vulnerability aligns with CWE-284 Access Control Issues and can be categorized under ATT&CK technique T1548.001 for abuse of privileges and T1070.004 for indicator removal. Organizations should also consider implementing network-based monitoring solutions to detect potential unauthorized access attempts that might exploit this screen locking failure, as the vulnerability creates a persistent security gap that requires continuous vigilance and management.