Dear Amit Klein (AKsecurity), --Monday, July 18, 2005, 9:40:32 PM, you wrote to bugtraq@xxxxxxxxxxxxxxxxx: AKA> NTLM HTTP Authentication AKA> (and possibly other connection-oriented AKA> HTTP authentication and authorization protocols) AKA> is insecure by design NTLM authentication is insecure by design for external authentication, because of "single signon" ideology. NTLM authentication can be used for NTLM proxy attack. For example, attacker who can hijack or spoof server connection with NTLM authentication can use this connection to access different Web server, mail server or file server with client's credentials. This is known for many years and was discussed for many times. Few years ago Internet Explorer was patched to use NTLM authentication only for local network zone. Local network are hosts with NetBIOS name (for example WEBSRV, excluded by default from proxy) and list of proxy exclusions. So, under default configuration, NTLM will not be used through proxy server, at least in Internet Explorer. -- ~/ZARAZA http://www.security.nnov.ru/
