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I read on line that it is possible to change the LCD display of most printers by simply sending a TCP packet to it. I tried that, and It works.

I have been wondering why printer's manufacturers have not fixed the issue? since it is some sort of security leak.

Thanks for any ideas.

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Why do you think it's a security leak? – ChrisF Jun 21 '10 at 13:42
It's a printer, not a file server containing sensible data. Anyways... do we have to debate or it's an issue you're experiencing? – r0ca Jun 21 '10 at 13:47
Most vendors would describe this as a "feature", not a "bug". After all, this (sending "@PJL ..."-commands to printers) is how they make the LCD to show "Printing job 'word.doc' by user cathy02". But, in their defense, we have to say that most vendors also do include security measures that can make it very difficult for arbitrary users to send a "Kick my lower tray twice" message. It's up to your printer admin to make it more secure. – Kurt Pfeifle Jul 5 '10 at 21:04
up vote 4 down vote accepted

Most printers also have security permissions which prevent this sort of fun (or abuse, depending on your point of view). If you wish to control this, restrict the systems allowed to send the printer jobs using the printer's IP filter to only a secured print server, and do not allow users to execute applications or code on the print server. Otherwise, you've much bigger issues regarding printer abuse than simply stopping people from making the LCD display "Insert Coin".

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wahahahahahahahah – kokbira Jun 21 '10 at 16:52
ROTFL :D – user40089 Jul 7 '10 at 2:02

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