What could happen if a well-known administrator password is used on a router?

Using a well-known administrator password on a router significantly compromises the security of the network. Such passwords are often easily guessed or widely recognized in the IT community. When unauthorized users gain access with a common password, they can manipulate the router's configuration, access sensitive information, and potentially disrupt network operations.

This situation can lead to a range of security issues, including data breaches, unauthorized network access, and other forms of cyberattacks. Strong, unique passwords are critical for protecting network devices, ensuring only authorized individuals can make changes to settings or view sensitive information. Therefore, the choice highlighting the risk of unauthorized access due to the use of a well-known password effectively underscores the importance of robust network security practices.