Can the tax authorities make retroactive corrections to the taxation at source?

If source taxes were underwithheld due to an error by the employer (false application of tariff and/or determination of wrong gross salary) the cantonal tax office has the right to reassess the source tax retroactively 5 years after the respective tax year has passed. After 5 years the cantonal tax office reserves the right to collect the additional tax by initiating a post-tax procedure.