Shared printer and security

[lowrider69]

What's the security risk if you have Windows 7 x64 and only share the printer and nothing else? This may be a silly question or maybe not, but can a worm spread over the network onto a system with a shared printer? I'm not a novice but I wondered about this. Logically to me it would be hard to do if nothing else is shared because the worm has no place to copy itself to(no shared folders or drives). Maybe the experts can fill me in.