Executive brief
A vulnerability in the configuration files of Linuxfabrik Monitoring Plugins allows a user with monitoring privileges to gain full administrative (root) control over the server. The software incorrectly allows the monitoring user to run system update commands with arbitrary options, which can be manipulated to launch a command shell with elevated permissions. This could allow an attacker who has already gained a foothold on the system to take complete control of the infrastructure.
Technical details
The vulnerability is classified as an argument injection (CWE-88) within the 'Debian.sudoers' file provided by Linuxfabrik Monitoring Plugins. The configuration allows the 'nagios' user to execute '/usr/bin/apt-get' via sudo without restricting the allowed arguments. An attacker with access to the nagios account can exploit this by passing the '-o APT::Update::Pre-Invoke' option to 'apt-get update', triggering the execution of an arbitrary shell as the root user. This local privilege escalation requires high privileges (access to the nagios account) but no user interaction. The issue is addressed in version 5.1.0 by restricting sudoers entries to specific, safe command arguments.
Affected products
- Linuxfabrik monitoring-plugins <= 5.0.0
- Linuxfabrik linuxfabrik-lib <= 5.0.0
Timeline
- 2026-05-29: disclosed
- 2026-07-02: advisory: GitHub Advisory published
- 2026-07-02: patched