Submitted by Aymen0909, also found by tapir (1, 2, 3), crypticdefense, gjaldon, eeshenggoh, gumgumzum, 0x73696d616f, LessDupes, GoatedAudits, and pauliax
https://github.com/code-423n4/2024-04-renzo/blob/main/contracts/Delegation/OperatorDelegator.sol#L299-L303
https://github.com/code-423n4/2024-04-renzo/blob/main/contracts/Deposits/DepositQueue.sol#L134-L137
When the OperatorDelegator::completeQueuedWithdrawal function is invoked to finalize a withdrawal from EL, it attempts to utilize the accumulated ERC20 tokens to fill the ERC20 withdrawal buffer, as demonstrated in the code snippet below:
The function iterates over the withdrawn tokens array and, for each token, checks if the withdrawal buffer needs filling. If required, the function attempts to call the depositQueue::fillERC20withdrawBuffer function, which is responsible for directing the ERC20 to the withdrawal queue contract to fill the buffer.
The issue arises because the depositQueue::fillERC20withdrawBuffer function can only be accessed by the RestakeManager contract, as it enforces the onlyRestakeManager modifier, as depicted below:
Consequently, when the completeQueuedWithdrawal function attempts this call, it reverts because OperatorDelegator lacks access to the depositQueue::fillERC20withdrawBuffer function. This results in the entire withdrawal completion call reverting, rendering it impossible for the admin to retrieve funds from EL.
In summary, this issue triggers a persistent DOS of the OperatorDelegator::completeQueuedWithdrawal function, preventing the protocol and users from withdrawing funds from EL and resulting in a loss of funds.
Persistent DOS of the OperatorDelegator::completeQueuedWithdrawal function, preventing the protocol from withdrawing funds from EL and leading to fund losses for the protocol and users.
VS Code
The simplest resolution is to grant access to the depositQueue::fillERC20withdrawBuffer function to everyone by removing the onlyRestakeManager modifier. This adjustment introduces no vulnerabilities to the protocol since any user calling it effectively donates funds to the protocol (to the withdrawal queue).
DoS
jatinj615 (Renzo) confirmed
Renzo mitigated
Status: Mitigation confirmed. Full details in reports from 0xCiphky, grearlake, Fassi_Security, Bauchibred, and LessDupes.
