Searching for Supersymmetry in the three- and four lepton final states with the CMS-Detector at the LHC

Data collected by the CMS Detector at the LHC in 2012 is analyzed. The three and the four lepton final state are of special interest because of the low predictions form Standard Model (SM) processes. The predictions of the SM are validated and limits on parameters of the supersymmetric extension of the SM are set.