The user can't recive rewards if token is USDT

Summary

The protocol currently these any tokens:

Which ERC20 tokens do you expect will interact with the smart contracts?

Any

Some tokens will revert when updating the allowance. They must first be approved by zero and then the actual allowance must be approved.

Vulnerability Detail

Тhe problem occurs in _claimEpochRewards():

504: payoutToken.approve(address(optionTeller), rewards);

Some ERC20 tokens (like USDT) do not work when changing the allowance from an existing non-zero allowance value. For example Tether (USDT)'s approve() function will revert if the current approval is not zero, to protect against front-running changes of approvals.

Impact

The protocol will impossible to use USDT token.

Code Snippet

https://github.com/sherlock-audit/2023-06-bond/blob/main/options/src/fixed-strike/liquidity-mining/OTLM.sol#L504

Tool used

Manual Review

Recommendation

It is recommended to set the allowance to zero before increasing the allowance.

Duplicate of #86

sherlock-audit / 2023-06-bond-judging

tsvetanovv - The user can't recive rewards if token is USDT #96