CVE-1999-0860 is a vulnerability in the Solaris operating system's chkperm utility, affecting versions 2.5.1, 2.6, 7.0, 5.5.1, and 5.7. The vulnerability arises because chkperm improperly handles the VMSYS environment variable, allowing local users to exploit a symlink attack to read files owned by the 'bin' user. Specifically, by manipulating the VMSYS variable and creating symbolic links, an attacker with local access can trick chkperm into reading files that should otherwise be inaccessible. This vulnerability does not require authentication beyond local user access and does not allow modification or deletion of files, only unauthorized reading. The CVSS score is 2.1 (low severity), reflecting limited impact and the requirement for local access. No patch is available, and there are no known exploits in the wild. The vulnerability primarily compromises confidentiality of certain files owned by 'bin' but does not affect integrity or availability. Given the age of the affected Solaris versions, this vulnerability is mostly relevant in legacy environments still running these outdated systems.

For European organizations, the impact of this vulnerability is generally low due to the requirement for local user access and the limited scope of information disclosure. However, organizations that still operate legacy Solaris systems in critical infrastructure, industrial control, or specialized environments could face confidentiality risks if unauthorized local users gain access. Disclosure of sensitive files owned by 'bin' could potentially reveal system configuration or operational details that aid further attacks. While the vulnerability does not allow privilege escalation or system disruption, any unauthorized data access is a concern under European data protection regulations such as GDPR. The risk is mitigated by the rarity of these Solaris versions in modern deployments and the absence of known active exploitation campaigns.

Since no official patch is available, mitigation should focus on reducing local user access and monitoring. Organizations should: 1) Restrict local user accounts and enforce strict access controls to prevent unauthorized logins on Solaris systems. 2) Audit and monitor usage of chkperm and environment variables like VMSYS to detect suspicious activity or symlink manipulations. 3) Consider removing or disabling chkperm if it is not essential to system operations. 4) Upgrade legacy Solaris systems to supported versions or migrate to modern platforms where this vulnerability is not present. 5) Employ file integrity monitoring on critical system files owned by 'bin' to detect unauthorized reads or changes. 6) Implement network segmentation to isolate legacy Solaris hosts and limit exposure. These steps go beyond generic advice by focusing on environment variable handling, symlink attack vectors, and legacy system management.