A Use of Hard-coded Credentials issue was discovered in Smiths Medical Medfusion 4000 Wireless Syringe Infusion Pump, Version 1.1, 1.5, and 1.6. The pump with default network configuration uses hard-coded credentials to automatically establish a wireless network connection. The pump will establish a wireless network connection even if the pump is Ethernet connected and active; however, if the wireless association is established and the Ethernet cable is attached, the pump does not attach the network stack to the wireless network. In this scenario, all network traffic is instead directed over the wired Ethernet connection.