Attacker can frontrun deployVault to deploy at the same address

[code423n4]

Lines of code

https://github.com/GenerationSoftware/pt-v5-vault/blob/b1deb5d494c25f885c34c83f014c8a855c5e2749/src/VaultFactory.sol#L67-L78

Vulnerability details

Impact

Vaults are created from the factory via CREATE1, an attacker can frontrun deployVault to deploy at the same address but with different config. If the deployed chain reorg, a different vault might also be deployed at the same address.

Proof of Concept

https://github.com/GenerationSoftware/pt-v5-vault/blob/b1deb5d494c25f885c34c83f014c8a855c5e2749/src/VaultFactory.sol#L67-L78

1. Bob setup a bot to monitor the mempool when PT deploy a new vault
2. Bob's bot saw a deployment by PT at 0x1234, fire a tx to deposit immediately
3. Alice frontrun PT's deployment by deploying a malicious vault at 0x1234
4. Bob's transaction ended up deposited into Alice's malicious vault

Recommended Mitigation Steps

Use CREATE2 and the vault config as salt.

Assessed type

MEV

[c4-judge]

Picodes marked the issue as primary issue

[asselstine]

The Vault address is derivative of the (sender address, nonce). I don't see how this scenario is possible?

[c4-sponsor]

asselstine marked the issue as sponsor disputed

[Picodes]

@asselstine exactly, so here it only depends on the nonce of the factory, so in case of reorg someone could "override" a vault deployment and all following transactions would still be executed

[c4-judge]

Picodes marked the issue as satisfactory

[c4-judge]

Picodes marked the issue as selected for report

[asselstine]

Fixed GenerationSoftware/pt-v5-vault#25