Use proxy clones to create Synths & LPTokens

[code423n4]

Handle

nathaniel

Vulnerability details

Impact

In SynthFactory, the number of Synths will likely be equal to the number of unique foreign tokens in the protocol. Using proxy clones instead of deploying the entire contract can greatly reduce gas fees (~860,000 -> ~150,000 by my estimate testing with Remix). The change is as follows:

• Change the Synth base contract from ERC20 to ERC20Upgradeable.
• Replace the Synth constructor with an initialize function.
• In createSynth, leverage openZeppelins proxy clone to clone the Synth contract and then immediately run the initializer on the clone synthClone.initialize(token)
  The same pattern could be implemented for LPTokens.

Proof of Concept

https://github.com/code-423n4/2021-11-vader/blob/main/contracts/dex-v2/synths/SynthFactory.sol#L31
https://github.com/code-423n4/2021-11-vader/blob/main/contracts/dex-v2/wrapper/LPWrapper.sol#L29
https://docs.openzeppelin.com/contracts/4.x/api/proxy#Clones

Tools Used

manual review