BlockDev Sp. Z o.o: Steal ALL collateral during liquidation by exploiting lack of validation in `flip.kick`

Summary: The flip contract allows for the MCD system to auction collateral in exchange for DAI. A lack of validation in the method flip.kick allows an attacker to create an auction with a fake bid value. Since the end contract trusts that value, it can be exploited to issue any amount of free DAI...

BlockDev Sp. Z o.o: Steal collateral during `end` process, by earning DSR interest after `flow`.

Summary: The end contract in MCD controls the process of shutting down the MCD contracts and allowing for users to redeem their DAI for collateral -- presumably to migrate to a new implementation of DAI. The process, however, doesn't prevent the continued functioniong of DAI savings accounts pot...