Submission Details
Severity:
Ignores return value after token approvals
Summary
In the contracts mentioned below, after approving a token, the return value `bool` is ignored. If the approval fails but the error is not checked, any subsequent transfers relying on that approval will also fail. This is an issue because, the contract assumes the token is approved for transfers but cannot verify it.
Vulnerability Details
```javascript
function _increaseAllowance(address spender, uint256 amount) internal {
=> feeToken.approve(spender, feeToken.allowance(address(this), spender) + amount);
}
```
found in
1.`LLMOracleCoordinator.sol::_increaseAllowance()`
2. `LLMOracleRegistry.sol::unregister()`
3. in the constructor of `BuyerAgent.sol`
Impact
if funds are held but cannot be transferred as intended, users might lose trust on the protocol and repeated unexpected reverts or failed transactions can impact the smooth operation of the protocol.
Tools Used
slither , manual review
Recommendations
1.use `SafeERC20` library from openzeppelin.(reccomended)
2.manually handle the return values.
Prize pool breakdown
Total prize
21,000 USDC
nSLOC
1,03420
USDC / LOC
20,000 USDC
1,000 USDC
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