CVE-1999-1165 is a high-severity vulnerability affecting GNU fingerd version 1.37, a daemon that provides finger protocol services to query user information on Unix-like systems. The core issue is that fingerd 1.37 does not properly drop elevated privileges before accessing user information files such as .fingerrc, .plan, .forward, or .project. This improper privilege management allows a local attacker to exploit two main attack vectors: (1) by placing a malicious program in the .fingerrc file, an attacker can escalate their privileges to root, effectively gaining full control over the system; (2) by leveraging symbolic links in .plan, .forward, or .project files, an attacker can read arbitrary files on the system, potentially exposing sensitive information. The vulnerability is local, requiring access to the system, but does not require authentication, and the attack complexity is low. The CVSS v2 score of 7.2 reflects the critical impact on confidentiality, integrity, and availability due to privilege escalation and unauthorized file access. No patches are available, and no known exploits in the wild have been reported, likely due to the age of the software and its declining use. However, systems still running this outdated version remain at risk if local access is obtained.

For European organizations, the impact of this vulnerability depends largely on whether GNU fingerd 1.37 is in use within their infrastructure. While fingerd is largely obsolete and replaced by more secure alternatives, legacy systems or specialized environments might still run this daemon. Successful exploitation could lead to full system compromise via root privilege escalation, allowing attackers to manipulate system configurations, install persistent malware, or exfiltrate sensitive data. The ability to read arbitrary files could expose confidential information, including user credentials, configuration files, or proprietary data. This poses a significant risk to organizations handling sensitive personal data under GDPR, as unauthorized access and data breaches could lead to regulatory penalties and reputational damage. Additionally, compromised systems could be leveraged as footholds for lateral movement within networks, increasing the risk of broader organizational compromise.

Given the absence of an official patch, European organizations should prioritize the following mitigations: (1) Identify and inventory all systems running GNU fingerd 1.37 or similar legacy finger daemons. (2) Disable the fingerd service entirely if it is not strictly necessary, as the finger protocol is largely deprecated and considered insecure. (3) If the service must remain active, run it within a restricted environment or container with minimal privileges and access controls to limit potential damage. (4) Implement strict file system permissions to prevent local users from modifying .fingerrc, .plan, .forward, or .project files, and disallow symbolic links in these files. (5) Monitor local user activities and audit logs for suspicious access patterns or privilege escalations. (6) Consider migrating to modern, secure user information services that follow current security best practices. (7) Enforce strong local user account controls and limit local access to trusted personnel only.