NftSettingsRegistry Manual Review Findings

NSR-01M: Improper Validation of Slippage Values

Type	Severity	Location
Input Sanitization		NftSettingsRegistry.sol: • I-1: L289 • I-2: L358

Description:

The referenced slippage values defined in basis points are insufficiently validated as they are permitted to be 0.

Impact:

A slippage value of 0 is effectively invalid as the likelihood of the associated operation reverting is significantly high.

Example:

Copy
271if (!settings.autoExit) {
272    if (
273        settings.exitConfig.triggerTickLow != 0
274            || settings.exitConfig.triggerTickHigh != 0
275            || settings.exitConfig.exitTokenOutLow != address(0)
276            || settings.exitConfig.exitTokenOutHigh != address(0)
277            || settings.exitConfig.slippageBP != 0
278            || settings.exitConfig.priceImpactBP != 0
279    ) {
280        revert AutoExitNotSet();
281    }
282} else {
283    if (
284        settings.exitConfig.triggerTickLow == 0
285            && settings.exitConfig.triggerTickHigh == 0
286    ) {
287        revert ExitTriggersNotSet();
288    }
289    if (settings.exitConfig.slippageBP > MAX_SLIPPAGE_BP) {
290        revert InvalidSlippageBP();
291    }
292    if (
293        settings.exitConfig.priceImpactBP > MAX_PRICE_IMPACT_BP
294            || settings.exitConfig.priceImpactBP == 0
295    ) {
296        revert InvalidPriceImpactBP();
297    }
298}

Recommendation:

Similarly to other configurational variables, we advise them to be sanitized as being non-zero so as to ensure valid slippage configuration values.

Alleviation (6ab7af3bb495b817ffec469255ea679b1813eecb):

The vfat team evaluated this exhibit and stated that a zero-value slippage is desirable.

While the code will behave as expected when the zero-value slippage is imposed, the dynamic conditions of the market will significantly increase the likelihood of such a transaction reverting and would usually indicate malformed input.

In any case, as the vfat team wishes to retain this behaviour as acceptable within their codebase we consider this exhibit to be acknowledged.