code423n4 commented 2 years ago

Lines of code

https://github.com/code-423n4/2022-09-artgobblers/blob/fb54f92ffcb0c13e72c84cde24c138866d9988e8/src/ArtGobblers.sol#L560 https://github.com/transmissions11/solmate/blob/34d20fc027fe8d50da71428687024a29dc01748b/src/auth/Owned.sol#L39 https://github.com/code-423n4/2022-09-artgobblers/blob/fb54f92ffcb0c13e72c84cde24c138866d9988e8/src/utils/GobblerReserve.sol#L34

Vulnerability details

Single-step process for critical ownership transfer is risky

Impact

The following contracts and functions, allow owners to interact with core functions such as: Functions from ArtGobblers.sol:

upgradeRandProvider() -> to update rand provider, what can be important in some future

Functions from Owned.sol:

setOwner() to set new Owners

Functions from GobblerReserve.sol:

withdraw() -> To withdraw all gobblers NFT from the reserve

Such critical address transfer in Owned.sol one-step is very risky because it is irrecoverable from any mistakes

Scenario: If an incorrect address, e.g. for which the private key is not known, is used accidentally then it prevents the use of all the onlyOwner() functions forever, which includes the changing of various critical addresses and parameters. This use of incorrect address may not even be immediately apparent given that these functions are probably not used immediately.

When noticed, due to a failing onlyOwner() function call, it will force the redeployment of these contracts and require appropriate changes and notifications for switching from the old to new address. This will diminish trust in the protocol and incur a significant reputational damage.

Also neither the constructor neither setOwner check for 0 address, what makes this more feasible to happen

Github Permalinks

https://github.com/code-423n4/2022-09-artgobblers/blob/fb54f92ffcb0c13e72c84cde24c138866d9988e8/src/ArtGobblers.sol#L560

https://github.com/transmissions11/solmate/blob/34d20fc027fe8d50da71428687024a29dc01748b/src/auth/Owned.sol#L39

https://github.com/code-423n4/2022-09-artgobblers/blob/fb54f92ffcb0c13e72c84cde24c138866d9988e8/src/utils/GobblerReserve.sol#L34

Proof of Concept

See similar High Risk severity finding from Trail-of-Bits Audit of Hermez. https://github.com/trailofbits/publications/blob/master/reviews/hermez.pdf See similar Medium Risk severity finding from Trail-of-Bits Audit of Uniswap V3: https://github.com/Uniswap/v3-core/blob/main/audits/tob/audit.pdf

Recommended steps

Recommend use functions for a two-step address change:

Approve a new address as a pendingOwner
A transaction from the pendingOwner address claims the pending ownership change.

This mitigates risk because if an incorrect address is used in step (1) then it can be fixed by re-approving the correct address. Only after a correct address is used in step (1) can step (2) happen and complete the address/ownership change.

Also, consider adding a time-delay for such sensitive actions. And at a minimum, use a multisig owner address and not an EOA.

Shungy commented 2 years ago

Design choice. This is informational or low risk at most. Not med.

GalloDaSballo commented 2 years ago

2 step check is historically non-critical, will downgrade