Using a credit card you start incurring interest charges, at whatever rate the cc charges, immediately. A credit card for a cash advance is only for dire emergencies.
Again, I would urge anyone to check terms of their credit card and any other options at their disposal. I always see ABSOLUTELY DO NOT and ONLY IN DIRE EMERGENCIES and it really does not help in giving advice.
On here, many people will discuss fees they incur with an ATM card, and in the end say "Oh well, I am paying $$$$ for a trip, so if I pay some money to get some cash...no big deal"
For example, Bank of America, which many people use, will charge you a $5 fee to use your card out of network plus a 3% of the transaction as a currency conversion fee. So to take out 200 euro (OK let's say at this time it is 1:1) it would cost you $211 ($200 plus $5 fee plus 3% of $200, so $6) Yes, you can spend your time looking for an ATM that is aligned with BoA, in Germany maybe not too bad, but whatever, you save yourself $5.
Most credit cards offer cash advance. The most common terms are a $10 minimum fee or 5% of transaction amount. This means if you seek a cash advance of 200 euro (again, lets assume 1:1) you will be charged $210...so less than a BoA cardholder will see!
Of course many will also say "OH MY GOD...YOU WILL PAY 24% INTEREST FROM THE SECOND YOU TAKE THAT MONEY OUT!!!!!"
But do the math. First, yes, you can go on immediately and pay off the balance (If you had cash in the bank for an ATM withdrawal, then you can pay the card). Secure connection? All my credit cards have two factor authentification..so no issue there, if you do not, that, and your risk, is on your credit card company. But let's say you hold that $200 until your next pay cycle, How much interest will you incur? (It is less than many doomsayers think)