Summary

the _inceaseAllowance function calculates the allowance for the spender address with additional amount`

Vulnerability Details

the LLMOracle is vulnerable to a well- known race condition in the ERC20 standard. This race condition can occur when a user calls the approve function of an ERC20 token, then calls a transferFrom on the same token.

before the `feeToken.approves the spender could call transferFrom between the allowance check and the approve, thereby transfering the allowance before the approval is made, this sets the allowance to 0 which makes possible to approve the initial allowance + amount

`

Impact

likelihood: medium, unintended funds get withdrawn from the contract.

Tools Used

Manual Review

Recommendations

The issue can be mitigated by the use of increaseAllowance and decreaseAllowance functions to modify the approvals.