Academic Researchers have unearthed several serious vulnerabilities in printers which affect 20-30 of the most popular printers by top 10 printer makers. The printers on which these vulnerabilities were tested were the daily use printers found in universities and most offices.
Since these vulnerabilities were found by academics for their thesis, the printers they used to test were a pool of printers used regularly out of which some even weren’t completely functional. These network printers included the ones built by Dell, HP, Samsung, Brother, Konica, Lexmark and others which even had unpatched vulnerabilities discovered few years ago.
The research published six security exploits along with a blog post, a wiki of all the tested printers and a open-source toolkit which one could use to steal passwords, shut down printers, hijack network printers, remotely steal stored copies of printed documents and even cause physical damage within 24hours of access by stressing the components with a DoS attack.
The toolkit is meant to be a tool to test the printer security and not be used for malicious attacks. The toolkit connects to the device via network or USB and exploits the features of the given printer language. Apparently, there are dozens of languages via which a printer can be controlled. Some are meant to control the printer, some of send print commands and some to set print jobs. Out of which the research focuses on just three of them to test these vulnerabilities. These are selected as they are spoken by most laser printers.
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The toolkit isn’t a malicious code but instead it takes simple printer commands, converts it into complex printer language and returns it in a simple format. If used by hackers, they can have access to all the printer memory and take any document or data stored in it which could include your network passwords for wireless printing or email sharing or fax or scanning, your last printed document which could be anything from private contract papers to sensitive personal information based on what the printer is used for.
The team contacted all the affected vendors in October 2016 and Dell was the only one to reply. Despite the latest firmware installed on all the printers before testing, these exploits exist and many of those were even in 5-year-old printers.
For more details read ZDNET report which includes inputs by Jens Muller, who worked with his colleagues for almost a year to develop the toolkit for testing.