#vulnerable code 
                                public static String getMusterPfadVlc() {
        final String PFAD_LINUX_VLC = "/usr/bin/vlc";
        final String PFAD_MAC_VLC = "/Applications/VLC.app/Contents/MacOS/VLC";
        String pfad = "";
        if (System.getProperty("os.name").toLowerCase().contains("windows")) {
            pfad = getWindowsVlcPath();
        } else if (System.getProperty("os.name").toLowerCase().contains("linux")) {
            pfad = PFAD_LINUX_VLC;
        } else if (System.getProperty("os.name").toLowerCase().contains("mac")) {
            pfad = PFAD_MAC_VLC;
        }
        if (new File(pfad).exists()) {
            return pfad;
        } else {
            return "";
        }
    } 
                            #location 9 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                public static String getMusterPfadVlc() {
        final String PFAD_LINUX_VLC = "/usr/bin/vlc";
        final String PFAD_MAC_VLC = "/Applications/VLC.app/Contents/MacOS/VLC";
        final String PFAD_WIN_DEFAULT = "C:\\Programme\\VideoLAN\\VLC\\vlc.exe";
        final String PFAD_WIN = "\\VideoLAN\\VLC\\vlc.exe";
        String pfad;
        switch (getOs()) {
            case OS_LINUX:
                pfad = PFAD_LINUX_VLC;
                break;
            case OS_MAC:
                pfad = PFAD_MAC_VLC;
                break;
            case OS_WIN_32BIT:
            case OS_WIN_64BIT:
            case OS_UNKNOWN:
            default:
                if (System.getenv("ProgramFiles") != null) {
                    pfad = System.getenv("ProgramFiles") + PFAD_WIN;
                } else if (System.getenv("ProgramFiles(x86)") != null) {
                    pfad = System.getenv("ProgramFiles(x86)") + PFAD_WIN;
                } else {
                    pfad = PFAD_WIN_DEFAULT;
                }
        }
        if (!new File(pfad).exists()) {
            pfad = "";
        }
        return pfad;
    }