I believe these vulnerabilities only allow RCE as the 'lp' user (which is able to access parallel ports and USB devices that identify themselves as printers). I

I believe these vulnerabilities only allow RCE as the 'lp' user (which is able to access parallel ports and USB devices that identify themselves as printers). In addition the process will be confined by MAC policies (e.g., on Fedora/Red Hat I think they're confined by cupsd_t).