And SPNs can be linked to service accounts, and not necessary to computer accounts only. The authorized servers fields allows “*” wildcards and it is common to see “TERMSRV/*” or “TERMSRV/*.” (“TERMSRV” means RDP), or the same with “HOST/*” prefix, or even just plain “*”! Actually, the UI mentions “servers” but since the SPN notation is used, it should be more appropriate to speak of “authorized services” as not all services hosted by a server are authorized. Many tutorials, and even Microsoft tools apparently, change these settings.
#LOCAL DYNAMODB NO CREDENTIALS ERROR WINDOWS#
Whereas, if I understood correctly “fresh credentials” are for example the one you type when connecting to the remote server with RDP, and “saved credentials” are credentials you saved in your Windows vault (see mimikatz vault. “Default credentials” are what interest us here since they are the current credentials for the authenticated user. We see similar options for different types: To be active, they must be enabled, then one or more authorized servers must be defined. Some of them are “Allow” settings while others are “Deny”. We can find them in a Group Policy (GPO) editor under “Computer Configuration\Administrative Templates\System\Credentials Delegation”
#LOCAL DYNAMODB NO CREDENTIALS ERROR PASSWORD#
If your RDP client opens a graphical session, and you type your password on the remote server, then NLA is not used.Īs I said, some settings are required for this to work, what are they? If you type credentials in a box on your client, then NLA is used. NLA is Network-Level Authentication and it allows to authenticate before opening the graphical session. Note also that, for RDP, this works only with servers where NLA is enabled.
PowerShell remoting, Microsoft Virtual Console Service, remote Visual Studio debug, etc.) can use this and be enabled instead, so read the rest anyway! Hint ? : in your environment, if you always type your password when connecting with RDP, even with your own current account: then it means that these settings are probably not enabled… But it can be more complicated than that, for instance other services than RDP (e.g. For purists: note that these acronyms are not on the same level, “SSP” = Security Support Provider, “TSSSP” = “Terminal Services SSP”, and “TSPKG” is the Authentication Provider (it is implemented in mimikatz’s sekurlsa::logonpasswords and more precisely sekurlsa::tspkg).īenjamin Delpy reminded us in a 2016 tweet that credential delegation activation leads to presence of passwords in memory, even in Windows 10! Some settings are required for this to work, and by default none are configured which means that they are not enabled and this feature does not work… In the background, this RDP SSO features relies on the “CredSSP / TSSSP / TSPKG” components that allow “Credential Delegation”. ➡️ If you guessed that we could implement a malicious server and obtain the password: you are right! It is important since it means that your password is sent to the server, protected in transit of course, but still, the password is finally obtained in clear by the remote server.ĭo you see where we are going here? Take the time to guess what could go wrong… ? But, you should know that opening an RDP session translates to an interactive session opening on the server-side. If you use a Windows device joined to a domain, then you can connect remotely to a server using RDP with your current AD user account without having to re-type your password. RDP (Remote Desktop / Terminal Server) is compatible with SSO. You can skip the technical explanations and go directly to the exploitation steps. This article also allows defenders and systems owners to review the settings in their environments, and evaluate if they are at risk of credential theft using this technique.