Basic authentication is a simple and widely used method of user authentication for HTTP requests. When a client sends a request to a server that
requires authentication, the client includes the username and password (concatenated together and Base64 encoded) in the "Authorization" header of the
HTTP request. The server verifies the credentials and grants access if they are valid. Every request sent to the server to a protected endpoint must
include these credentials.
Basic authentication is considered insecure for several reasons:
- It transmits user credentials in plain text, making them susceptible to interception and eavesdropping.
- It relies solely on the server’s ability to verify the provided credentials. There is no mechanism for additional security measures like
multi-factor authentication or account lockouts after multiple failed login attempts.
- It does not provide a way to manage user sessions securely. The client typically includes the credentials in every request, which creates more
opportunities for an attacker to steal these credentials.
These security limitations make basic authentication an insecure choice for authentication or authorization over HTTP.
What is the potential impact?
Basic authentication transmits passwords in plain text, which makes it vulnerable to interception by attackers.
Session hijacking and man-in-the-middle attack
If an attacker gains access to the network traffic, they can easily capture the username and password. Basic authentication does not provide any
mechanism to protect against session hijacking attacks. Once a user is authenticated, the session identifier (the username and password) is sent in
clear text with each subsequent request. If attackers can intercept one request, they can use it to impersonate the authenticated user, gaining
unauthorized access to their account and potentially performing malicious actions.
Brute-force attacks
Basic authentication does not have any built-in protection against brute-force attacks. Attackers can repeatedly guess passwords until they find
the correct one, especially if weak or commonly used passwords are used. This can lead to unauthorized access to user accounts and potential data
breaches.
