#4 I found a vulnerability of SmartVault contract!!!

Severity

High Risk

Summary

I can mint you tokens(ex:EUROs) with almost zero collateral tokens.

Vulnerability Details

There is "swap" function for swaping collateral tokens in SmartVault contract. There's no problem if vault owner swaps collateral tokens before he mints EUROs. But what if he swaps collateral tokens after minting EUROs? In "swap" function "amountOutMinimum" is set to 0. So sandwitch attack is available.

Step 1: Hacker deposits collateral tokens(ARB tokens) into SmartVault.

Step 2: Hacker mints EUROs.

Step 3: Hacker swaps a lot of ARB tokens to WETH tokens in Uniswap v3.

Step 4: Hacker calls "swap" function of SmartVault, ARB tokens in SmartVault will be swapped to almost zero WETH tokens because of very high slippage.

Step 5: Hacker swaps WETH to ARB in Uniswap v3.

Impact

Finally hacker gets almost all ARB tokens deposited in SmartVault, so he can mint EUROs with almost zero collateral tokens(WETH).

Tools Used

Recommendations