Summary

In CurrencyManager contract functions addCurrency() and removeCurrency() are ignoring return values ofadd() and remove().

Vulnerability Details

CurrencyManager::addCurrency() ignores return value by _whitelistedCurrencies.add(currency) and then emit an event. If the currency was not added and the ignored return code is False, then and emited event will be incorrect!
Similarly CurrencyManager::removeCurrency() ignores return value by _whitelistedCurrencies.remove(currency) and in case of failed deletion an event will be emited that the deleting was done.

Impact

Incorrectly emited events.

Tools Used

Slither, manual review

Recommendations

Check return values are True, before emiting events.