Silent Failure in handleAgentTaxes

Summary

handleAgentTaxes() updates accounting state and records tax events before calling _swapForAsset(), but it ignores the result of that external call.

Because _swapForAsset() returns a boolean success indicator, the current implementation can treat failed swaps as if settlement succeeded.

Vulnerability details

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function handleAgentTaxes(
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    uint256 agentId,
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    bytes32[] memory txhashes,
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    uint256[] memory amounts,
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    uint256 minOutput
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) public onlyRole(EXECUTOR_ROLE) {
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    require(txhashes.length == amounts.length, "Unmatched inputs");
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    TaxAmounts storage agentAmounts = agentTaxAmounts[agentId];
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    uint256 totalAmount = 0;
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    for (uint i = 0; i < txhashes.length; i++) {
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        bytes32 txhash = txhashes[i];
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        if (taxHistory[txhash].agentId > 0) {
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            revert TxHashExists(txhash);
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        }
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        taxHistory[txhash] = TaxHistory(agentId, amounts[i]);
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        totalAmount += amounts[i];
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        emit TaxCollected(txhash, agentId, amounts[i]);
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    }
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    agentAmounts.amountCollected += totalAmount;
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    _swapForAsset(agentId, minOutput, maxSwapThreshold);
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}

Impact

The contract records tax processing in taxHistory and increases agentAmounts.amountCollected, while agentAmounts.amountSwapped depends on the swap path succeeding. If the swap fails:

• tax events remain marked as processed
• accounting state advances
• the asset conversion may never happen

That creates a mismatch between recorded state and actual settlement.

Recommendation

Check the return value from _swapForAsset() and either revert on failure or route failed swaps through an explicit retry or debt-accounting path. The state transition should not silently continue when the settlement leg fails.