The vulnerability arises from the Debian.sudoers file in Linuxfabrik Monitoring Plugins, where the nagios user is permitted to run /usr/bin/apt-get with unrestricted arguments via sudo. This lack of argument enforcement allows an attacker with access to the nagios user to execute arbitrary commands as root by passing crafted apt-get arguments, such as using the Pre-Invoke option to spawn a root shell. The issue is a local privilege escalation requiring prior access to the nagios account. The recommended remediation is to restrict the sudoers entry to only allow specific apt-get arguments used by the monitoring plugin, preventing arbitrary command execution.

This vulnerability allows a local attacker who has already compromised the nagios user account to escalate privileges to root by exploiting the unrestricted apt-get command execution via sudo. The impact is a full root shell on the affected system. However, exploitation requires prior access to the nagios user, which is a significant precondition.

No official patch is currently available. The recommended mitigation is to modify the sudoers file to restrict the apt-get command to only the specific arguments required by the monitoring plugin, for example, allowing only 'apt-get update --quiet 2'. This prevents arbitrary argument injection and privilege escalation. Users should review and tighten sudoers permissions accordingly.