CVE-1999-1025 is a vulnerability affecting the Common Desktop Environment (CDE) screen lock program (screenlock) on Solaris operating system versions 2.6 through 5.6. The issue arises specifically when the Solaris host is configured as an NIS+ client. Under these conditions, the screenlock program fails to properly lock an unprivileged user's console session. This improper locking mechanism allows an attacker with physical access to the console to bypass the screen lock by entering any string at the login prompt, effectively gaining unauthorized access to the system. The vulnerability stems from inadequate enforcement of session locking and authentication controls in the screenlock utility, which is intended to prevent unauthorized console access when a user leaves their session unattended. The CVSS v2 base score is 4.6 (medium severity), with an attack vector limited to local physical access (AV:L), low attack complexity (AC:L), no authentication required (Au:N), and partial impact on confidentiality, integrity, and availability (C:P/I:P/A:P). Although no known exploits have been reported in the wild, the vulnerability poses a risk in environments where physical security is not strictly enforced. A patch is available from the vendor (Sun Microsystems) to address this issue by correcting the screenlock behavior to properly enforce session locking on NIS+ client systems.

For European organizations, the impact of this vulnerability is primarily related to physical security and insider threat scenarios. Organizations using Solaris 2.6 to 5.6 systems configured as NIS+ clients may be at risk of unauthorized console access if an attacker gains physical access to the machine. This could lead to unauthorized disclosure of sensitive information, modification of system files or configurations, and potential disruption of services. While Solaris 2.6 and related versions are legacy systems and less common in modern infrastructures, some critical industrial, governmental, or legacy financial systems in Europe may still rely on these platforms. The vulnerability could undermine trust in system integrity and confidentiality, especially in environments with shared physical access or insufficient physical security controls. However, the requirement for physical access limits the scope of impact primarily to on-premises environments rather than remote attacks.

European organizations should prioritize patching affected Solaris systems by applying the vendor-provided fixes available at the referenced Sun Microsystems patch links. Additionally, organizations should enforce strict physical security controls around Solaris servers, including locked server rooms and restricted access to consoles. Where possible, upgrade legacy Solaris systems to supported versions or migrate to modern platforms with improved security features. Implementing multi-factor authentication for console access and using alternative screen locking mechanisms that are verified to enforce proper session locking can further reduce risk. Regular audits of physical access logs and monitoring for unauthorized access attempts should be conducted. For environments where patching or upgrading is not immediately feasible, consider disabling NIS+ client functionality or isolating affected systems from sensitive networks to minimize exposure.