CVE-1999-1400 in Screen Saver
Summary
by MITRE
The Economist screen saver 1999 with the "Password Protected" option enabled allows users with physical access to the machine to bypass the screen saver and read files by running Internet Explorer while the screen is still locked.
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Analysis
by VulDB Data Team • 04/19/2026
The vulnerability described in CVE-1999-1400 represents a critical security flaw in the Economist screen saver software version 1999 that was widely distributed in the late 1990s. This issue specifically affects systems where the screen saver is configured with the "Password Protected" feature enabled, creating a dangerous bypass mechanism that undermines the fundamental security purpose of screen savers. The vulnerability stems from a design flaw in how the screen saver handles process execution when the system is locked, allowing unauthorized access through a simple but effective technique that exploits the interaction between the screen saver and the web browser component.
The technical implementation of this vulnerability relies on the screen saver's failure to properly restrict access to system resources when the password protection mechanism is active. When a user with physical access to a locked machine runs Internet Explorer while the screen saver is active, the system allows the browser process to execute with elevated privileges that bypass the screen saver's intended lock mechanism. This occurs because the screen saver does not adequately monitor or restrict process execution that could potentially access protected files or system resources. The flaw operates at the operating system level where process creation and resource access controls are insufficiently enforced during the screen saver's locked state. This vulnerability aligns with CWE-284 Access Control issues, specifically representing improper access control when the system should be enforcing strict security boundaries.
The operational impact of this vulnerability is significant and directly threatens the confidentiality of sensitive information on affected systems. An attacker with physical access to a machine can bypass the screen saver protection without requiring any authentication credentials or specialized tools. This creates a serious risk for corporate and government environments where sensitive data might be stored on desktop computers. The vulnerability is particularly dangerous because it requires minimal technical knowledge to exploit, making it accessible to both malicious insiders and external attackers who gain physical access to systems. The attack vector is simple and reliable, as it only requires the user to launch Internet Explorer while the screen saver is active, which could easily occur during routine system use or as part of social engineering attacks.
Organizations affected by this vulnerability should implement immediate mitigations to prevent exploitation, including disabling the password-protected screen saver feature entirely or upgrading to patched versions of the software. System administrators should consider implementing additional security controls such as mandatory screen saver timeouts and ensuring that screen savers are properly configured with strong password requirements. The vulnerability demonstrates the importance of proper privilege separation and access control mechanisms in desktop security software, as outlined in the ATT&CK framework's privilege escalation techniques. Organizations should also conduct regular security assessments to identify similar flaws in other system components and ensure that all security features function as intended under various operational conditions. This vulnerability serves as a reminder that security controls must be robustly implemented and tested to prevent simple bypass techniques that could compromise entire systems.