Chintito,
I'm not fully up to speed with todays CDL's as I got mine about 6 years ago but from my experience a bank will consider people with poor credit history and they should not require any security or garentor for the loan, this is due to how a CDL works.
With a CDL the bank it self is not lending you the money but the government, the government has no means of directly lending money to people so has to employ the services of a high street bank (profitable for the bank, thats why they do it). So the government loans the money to the bank then the bank loans the money to you on their behalf so in affect the bank is nothing more than a go between for you and the government.
This means that banks are alot more flexible because they are not taking the risk and also it is the government who acts as the garentor on the loan, so from the banks point of view they cant lose because even if you take the money and do a runner it is the governments money not theirs.
This also means you can default on the loan without incurring penalties financially or with your credit rating, this is what happened to me, I could'nt find work flying and could'nt keep up the repayments therefore I defaulted on the loan, the bank was'nt bothered and just froze the loan which meant no more interest was inquired and I was able to pay off at a rate of my choosing. The bank said it dosent affect my credit rating as the CDL contract was with the government and they dont hold records of peoples financial history, in future it may affect my dealings with that particular bank but no other bank as they dont know about the CDL.
This means that you do stand a chance to get a CDL even with a poor credit history, from my experience my advice would be to try all the banks which offer CDL (their response to me differed alot) and when you've picked a bank try different branches ( I found different manages at different branches varied alot, some really froaned at me others were very helpfull and supportive and they all worked for the same bank.)
Hope this helps and good luck.