CVE-2017-20147 is a medium-severity vulnerability affecting the SmokePing monitoring tool, specifically the ebuild package smokeping-2.7.3-r1 on Gentoo Linux. The issue arises from the way the initscript manages the PID file used to track the SmokePing service process. This PID file is writable by the unprivileged 'smokeping' user. An attacker with smokeping user privileges can exploit this by writing arbitrary process IDs into the PID file. When the SmokePing service is stopped, the initscript reads the PID file and attempts to terminate the process with the specified PID. Because the PID file contents can be manipulated, the attacker can cause the initscript to send termination signals to arbitrary processes on the system, potentially killing critical system or application processes. This results in a denial of service (DoS) condition. The vulnerability does not affect confidentiality or integrity directly but impacts availability by enabling unauthorized termination of processes. Exploitation requires local access with smokeping user privileges but does not require user interaction. The CVSS v3.1 score is 6.5 (medium), reflecting network attack vector, low attack complexity, privileges required, no user interaction, unchanged scope, and impact limited to availability. The root cause is improper file permission management (CWE-377: Insecure Temporary File). No known public exploits have been reported. The vulnerability is specific to the Gentoo ebuild package for SmokePing version 2.7.3-r1, and no patch links are provided in the data, indicating that mitigation may require manual configuration changes or updates from maintainers.

For European organizations using Gentoo Linux with the vulnerable SmokePing package, this vulnerability poses a risk of local denial of service. SmokePing is a network latency monitoring tool often used in network operations centers to track network performance. If an attacker gains smokeping user access, they could disrupt monitoring services or cause collateral damage by terminating unrelated critical processes, potentially impacting network monitoring reliability and operational continuity. This could lead to delayed detection of network issues or outages, affecting service quality and incident response. While the vulnerability requires local access, in environments where multiple users have access or where the smokeping user privileges are not tightly controlled, the risk increases. European organizations with strict uptime and monitoring requirements, such as telecom providers, ISPs, and large enterprises with complex network infrastructures, could face operational disruptions. The impact on confidentiality and integrity is minimal, but availability degradation could have cascading effects on network management and incident handling.

To mitigate this vulnerability, European organizations should: 1) Immediately review and restrict file permissions on the SmokePing PID file to ensure it is not writable by the smokeping user or any unprivileged user. The PID file should be owned by root or the service manager with write permissions limited accordingly. 2) Upgrade to a fixed version of SmokePing or the Gentoo ebuild package once available, or apply vendor-provided patches if released. 3) Limit smokeping user privileges strictly to what is necessary, avoiding granting shell access or other capabilities that could facilitate local exploitation. 4) Implement monitoring and alerting for unexpected termination of critical processes to detect potential exploitation attempts. 5) Use system-level protections such as process accounting and auditd to track suspicious activities related to process termination. 6) Consider containerizing or sandboxing the SmokePing service to isolate it from critical system processes, reducing the blast radius of potential exploitation. 7) Regularly review and harden init scripts and service management configurations to prevent writable PID files or other insecure file permission issues.