The charity said it had referred more than 400 people to a foodbank in January, the highest monthly figure yet recorded.
CAS revealed the figures as MSPs prepare to debate foodbanks today. It said 30% of its referrals were because the person's benefit had been delayed and a further 22% had been penalised for alleged breaches of the rules. Another 14% had lost money after benefits were re-assessed; while 7% were affected by the so-called 'bedroom tax' which reduces housing benefit for those deemed to occupy homes too large for their needs.
CAS policy manager Keith Dryburgh commended the work of organisations such as the Trussell Trust which run foodbanks.
"But food parcels don't address the underlying problem of poverty, and should not be seen as a long-term solution to it," he said.
"The government's policies are leaving many people without the vital safety net that the welfare system is meant to provide. People should not need to go to a CAB or a food-bank because they have no money, and yet this is what CAB advisers see every week."
A UK Government spokesman said: "The benefits system supports millions of people who are on low incomes or unemployed and there is no robust evidence that welfare reforms are linked to increased use of food banks. In fact, our welfare reforms will improve the lives of some of the poorest families in our communities."