What is a primary risk factor when authenticating with a standard HTTP server?

The primary risk factor when authenticating with a standard HTTP server lies in the transmission of data in cleartext. This means that any data sent between the client (such as a user's web browser) and the server (the website being accessed) is not encrypted. As a result, information such as usernames, passwords, and other sensitive data can be easily intercepted by attackers through techniques like eavesdropping or man-in-the-middle attacks. Since the data is transmitted without encryption, anyone with access to the network can read it as it flows between the two parties.

The vulnerability presented by cleartext transmission emphasizes the importance of using secure protocols, such as HTTPS, which incorporates transport layer security (TLS) to encrypt data and protect it from unauthorized interception. This is crucial for safeguarding sensitive authentication information from being exploited.