system-config-printer: possible arbitrary code execution in pysmb.py due to improper escaping of hostnames

pysmb.py in system-config-printer 0.6.x and 0.7.x, as used in foomatic-gui and possibly other products, allows remote SMB servers to execute arbitrary commands via shell metacharacters in the 1 NetBIOS or 2 workgroup name, which are not properly handled when searching for network printers...