A default password is a standard pre-configured password for a device. Such passwords are the default configuration for many devices and, if unchanged, present a serious security risk. Typical examples of default passwords include admin, password and guest. Furthermore, a vendor generally uses a single default password, which can be easily found online through search or on websites that provide compiled lists.
Default passwords are commonly used for routers, access points, switches and firewalls. They are also common in embedded systems, industrial control systems (ICS) and remote terminal interfaces such as Telnet and SSH.
Left unchanged, default passwords provide an easy attack vector for home network equipment; if the owner also connects to a corporate network, that risk extends to the business as well. An attacker who logs into a device successfully is likely to have administrative-level access.
The risk is also severe in the case of embedded systems and ICS security because these environments were not originally intended to be accessible over the internet. However, in the burgeoning internet of things (IoT) environment, almost anything can be made addressible and connected, and while there are many benefits to IoT connectivity, enhanced security is not among them.
Default passwords are intended to be place holders and used only for the initial setup of hardware or after a factory reset. The user enters the password and is usually prompted to change it as part of the process, but not always.
To counteract the security issues of default passwords, device owners should change the default value to a strong password when they first configure a device. Vendors can enforce that change upon first use of the default password. Another option for the vendor is to employ secure unique default passwords.