FastNetMon Community Edition through 1.2.9 contains a configuration injection vulnerability in the Juniper router integration plugin. In src/juniper_plugin/fastnetmon_juniper.php, the $IP_ATTACK variable (received from argv[1]) is directly interpolated into Juniper NETCONF set-configuration commands at lines 69 and 90 without any validation or sanitization. Line 69: $conn->load_set_configuration("set routing-options static route {$IP_ATTACK} community 65535:666 discard"). Line 90: $conn->load_set_configuration("delete routing-options static route {$IP_ATTACK}/32"). An attacker who can control the IP address string can inject additional Juniper CLI configuration commands by embedding newline characters followed by arbitrary set/delete commands. This could modify the router's routing table, firewall filters, user accounts, or any other configuration element accessible via NETCONF. The impact is full router compromise.