CVE-1999-1092 is a vulnerability found in version 1.40 of the 'tin' Usenet newsreader client. The issue arises because tin creates a configuration directory named '.tin' with insecure file permissions. Specifically, the directory and its contained files, including '.inputhistory', are accessible to other local users on the same system. The '.inputhistory' file stores user input history, which in this case includes passwords or other sensitive credentials entered by the user. Because the directory permissions are not properly restricted, any local user on the system can read this file and extract passwords, leading to a compromise of user credentials. The vulnerability is classified with a CVSS score of 4.6 (medium severity), with the attack vector being local (AV:L), low attack complexity (AC:L), no authentication required (Au:N), and impacts on confidentiality, integrity, and availability (C:P/I:P/A:P). No patch is available for this vulnerability, and there are no known exploits in the wild. The vulnerability is primarily a local privilege information disclosure risk due to improper file permission settings in a legacy Usenet client software.

For European organizations, the direct impact of this vulnerability is limited primarily to environments where the tin 1.40 Usenet client is still in use. Given the age of the software (published in 1999) and the niche usage of Usenet clients today, the threat surface is relatively small. However, in legacy systems or specialized environments that still rely on tin for accessing Usenet or similar services, this vulnerability could allow a malicious local user to obtain passwords stored in the '.inputhistory' file. This could lead to unauthorized access to user accounts or other systems if those passwords are reused elsewhere. The compromise of credentials can also facilitate lateral movement within an organization's internal network, potentially escalating to more severe breaches. Confidentiality is primarily impacted, but integrity and availability could also be affected if attackers leverage the stolen credentials to modify or disrupt systems. The vulnerability requires local access, so remote exploitation is not possible, limiting the risk to insider threats or attackers who have already gained some level of access.

Since no official patch is available for tin 1.40, organizations should consider the following specific mitigation steps: 1) Restrict local user access on systems where tin is installed to trusted personnel only, minimizing the risk of malicious local users. 2) Manually adjust the permissions of the '.tin' directory and its contents to be accessible only by the owning user (e.g., chmod 700 for the directory and chmod 600 for files) to prevent other local users from reading sensitive files. 3) Avoid storing passwords or sensitive credentials in the '.inputhistory' file by configuring tin or the environment to disable history logging of sensitive inputs if possible. 4) Consider migrating away from tin 1.40 to more modern, actively maintained newsreader clients that follow secure file permission practices. 5) Monitor local system access logs for unusual activity that might indicate attempts to read user files. 6) Educate users about the risks of password reuse and encourage the use of unique, strong passwords and multi-factor authentication to limit the impact of credential disclosure.