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.
https://bugzilla.redhat.com/show_bug.cgi?id=728348
https://bugs.launchpad.net/ubuntu/+source/foomatic-gui/+bug/811119
http://www.securitytracker.com/id?1025967
http://www.redhat.com/support/errata/RHSA-2011-1196.html