Hard to answer with little info...BUT.. I am going to mae an assumption here.
IF the contract wasn't accepted by the bank yet, but they are making you sign additional addendum to present to the bank WITH your offer, then they are giving you the heads up that it can take 2-3 weeks to have bank approval of your offer, and then you have an additional 17 days to get the formal appraisal and loan commitment.
That means that you need to start on your mortgage application process (which will include the appraisal) as soon as you have your offer sent to the bank. Since a foreclosure usually doesn't allow for any repairs after home inspection, they are giving you in essence 4-5 weeks for the approval to be obtained which is very doable.
I have seen the banks grant a 7 day extension on this contingency and even the closing date (they usually give 45 days from acceptance of your offer to close).
I would make sure I was using an attorney and RE agent that are familiar with the process and have them be in close contact with the sellers agent, (and he/she in turn with the bank) to make sure you are protected along the way. Hope that helps.