hats-finance / Catalyst-Exchange-0x3026c1ea29bf1280f99b41934b2cb65d053c9db4

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The first depositor can perform a vault inflation attack on the vaults #79

Open hats-bug-reporter[bot] opened 10 months ago

hats-bug-reporter[bot] commented 10 months ago

Github username: -- Twitter username: -- Submission hash (on-chain): 0xaa998d418c81a4b7485ba8bc4fea1f8c8f7056eb0b05ed7794a3f522d119bce7 Severity: high

Description: Description\ Vaults are protected from first depositor manipulation attacks by either minting the vault's first tokens to the zero address or by deploying the vault with an initial balance (as it is in this case). If the vault's initial balance at deployment is zero, or the first tokens aren't being minted to the zero address, the vault will be vulnerable to the attack.

    function deployVault(
        address vaultTemplate,
        address[] calldata assets,
        uint256[] calldata init_balances,
        uint256[] calldata weights,
        uint256 amp,
        uint256 vaultFee,
        string memory name,
        string memory symbol,
        address chainInterface
    ) override external returns (address) {

https://github.com/catalystdao/catalyst/blob/27b4d0a2bca177aff00def8cd745623bfbf7cb6b/evm/src/CatalystFactory.sol#L65C1-L75C44

Attack Scenario\ Here's a good breakdown of the attack scenario by open zeppelin.

New vaults are at the greatest risk of inflation attacks. Let’s illustrate this with an example: Suppose a user is about to deposit 100 tokens into a new vault as the first depositor. If an attacker front-runs this initial deposit with even 1 wei, this minuscule deposit would still garner the attacker a 100% share of the pool.

Next, the attacker donates an amount greater than or equal to 100 tokens to the vault. This action increases the total balance of the pool, while maintaining the number of shares in circulation.

By the time the initial user’s deposit of 100 tokens makes it to the pool, the calculation for their share ends up being zero due to the way pool shares are calculated with the donated token balance (in this example, 100/101 rounds down to 0).

Finally, the attacker withdraws their share from the pool. Since they are the only one with any shares, this withdrawal equals the balance of the vault. This means the attacker also withdraws the 100 tokens deposited by the initial user, effectively stealing their deposit. full article

Potential fix

reednaa commented 10 months ago

Is this the check you want implemented? https://github.com/hats-finance/Catalyst-Exchange-0x3026c1ea29bf1280f99b41934b2cb65d053c9db4/blob/fba322fab023a9206183fb455e9f86facd550d8a/evm/src/CatalystVaultVolatile.sol#L113

https://github.com/hats-finance/Catalyst-Exchange-0x3026c1ea29bf1280f99b41934b2cb65d053c9db4/blob/fba322fab023a9206183fb455e9f86facd550d8a/evm/src/CatalystVaultAmplified.sol#L136