The `MultiSig` contract doesn't have a withdrawal mechanism in case there are funds are stuck in the contract.
[M-1] Summary
The MultiSig contract doesn't have a withdrawal mechanism in case there are funds are stuck in the contract.
Vulnerability Details
One of the owners of the MultiSig contract can be another contract, which might not implement logic which can invoke the approveTransaction function, or the contract might get selfdestructed. The create -> approve -> execute transaction flow is the only way to get funds out of the contract. Not being able to call approveTransaction would break this chain and result in the funds being stuck in the contract.
Impact
High impact - funds would be stuck in the contract. Medium likelihood - the owner could be another contract, which might not implement the required logic.
Tools Used
Manual review.
Recommendations
Implement a mechanism, by which each user could partially or fully retrieve their proportion of the funds in the contract. Such mechanism could be timer-based.
Appeal created
Users mistake, only impacting themselves.
Please read the CodeHawks documentation to know which submissions are valid. If you disagree, provide a coded PoC and explain the real likelihood and the detailed impact on the mainnet without any supposition (if, it could, etc) to prove your point.
Rewards breakdown
Live
The contest is live. Earn rewards by submitting a finding.
Appeals
This is your time to appeal against judgements on your submissions.
Appeals Review
Appeals are being carefully reviewed by our judges.