This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Security 6.4.1!

Password Erasure

After successful authentication, it is a security best practice to erase credentials from memory to prevent them from being exposed to potential memory dump attacks. ProviderManager in Spring Security supports this practice through the eraseCredentials method, which should be invoked after the authentication process is complete.

Best Practices

  • Immediate Erasure: Credentials should be erased immediately after they are no longer needed, which minimizes the window during which the credentials are exposed in memory.

  • Automatic Erasure: Configure ProviderManager to automatically erase credentials post-authentication by setting eraseCredentialsAfterAuthentication to true (the default).

  • Custom Erasure Strategies: Implement custom erasure strategies in custom AuthenticationManager implementations if the default erasure behavior does not meet specific security requirements.

Risk Assessment

Failure to properly erase credentials can lead to several risks:

  • Memory Access Attacks: Attackers can access raw credentials from memory through exploits like buffer overflow attacks or memory dumps.

  • Insider Threats: Malicious insiders with access to systems could potentially extract credentials from application memory.

  • Accidental Exposure: In multi-tenant environments, lingering credentials in memory could accidentally be exposed to other tenants.

Implementation

public class CustomAuthenticationManager implements AuthenticationManager {

	@Override
	public Authentication authenticate(Authentication authenticationRequest)
			throws AuthenticationException {

		Authentication authenticationResult;
		// TODO: Perform authentication checks...

		// Erase credentials post-check
		if (authenticationResult instanceof CredentialsContainer container) {
			container.eraseCredentials();
		}
	}

}

By implementing these practices, organizations can significantly enhance the security of their authentication systems by ensuring that credentials are not left exposed in system memory.