Vulnerabilities / Threats

7/25/2017
06:45 PM
50%
50%

How 'Postcript' Exploits Networked Printers

At Black Hat 2017, a university researcher will demo how attackers can drill into networked printers by way of the ubiquitous PostScript programming language.

Network printer exploits are like old dogs learning new tricks, according to a security researcher with Ruhr University.

In his upcoming Black Hat presentation, Exploiting Network Printers, Jens Muller, Ruhr University chair for network and data security will delve into an analysis of printer attacks, in which he discovered 20 printer models were all vulnerable to at least one of the same attacks that he tested. Muller will also disclose unusual ways the Internet is enabling network printer attacks via advanced cross-site printing techniques.

The vulnerability, Muller says, stems from the 35-year-old PostScript programming language, which has connected printers to end-users for decades, even as technology evolved from the parallel printer cable, to the USB stick, to networked printers, and today to the cloud.

"Before, printers used parallel cables and having PostScript wasn't a problem." Muller says. "But now, the printer manufacturers are still using PostScript and they can easily be exploited remotely."

PostScript: An Industry Standard 

The PostScript programming language is an industry standard for network printers and its use is ubiquitous. But despite attackers ability to exploit this language, printer manufacturers have largely looked the other way, he says. Instead, manufacturers put the onus on network administrators to place the printers inside the network, where the devices are presumed to be protected from outside threats.

Even today, he notes, manufacturers do not seem to realize that attackers can drill into networked printers by way of the Internet.

On the networking side, network administrators tend to view their connected printers as nothing more than a printing device, as opposed to a potential vector of attack, he says, noting that the end result is that network admins may not think it's important to secure network printers.

Some of the attacks Muller has tested include a denial of service attack that damaged eight of the 20 printers he was testing. One new issue to emerge is the ability to set a printer back to its factory defaults by taking control of the printer remotely. Other printer attacks range from stealing print jobs containing sensitive information to pilfering system files.

Work Arounds

One potential solution to the problem, Muller says, is to corral all the connected printers and put them on a separate network with a print server. The downside: it would require a network administrator to oversee two networks, which, he says, could be difficult for midsized companies and result in the additional costs of installing and monitoring a second firewall.

"What CISOs should really do is ask themselves do they really need a device connected," Muller says. "It may make sense not to connect the printer to the cloud."

Related Content:

Dawn Kawamoto is an Associate Editor for Dark Reading, where she covers cybersecurity news and trends. She is an award-winning journalist who has written and edited technology, management, leadership, career, finance, and innovation stories for such publications as CNET's ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Printers: The Weak Link in Enterprise Security
Kelly Sheridan, Associate Editor, Dark Reading,  10/16/2017
20 Questions to Ask Yourself before Giving a Security Conference Talk
Joshua Goldfarb, Co-founder & Chief Product Officer, IDDRA,  10/16/2017
Why Security Leaders Can't Afford to Be Just 'Left-Brained'
Bill Bradley, SVP, Cyber Engineering and Technical Services, CenturyLink,  10/17/2017
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Write a Caption, Win a Starbucks Card! Click Here
Latest Comment: This comment is waiting for review by our moderators.
Current Issue
Security Vulnerabilities: The Next Wave
Just when you thought it was safe, researchers have unveiled a new round of IT security flaws. Is your enterprise ready?
Flash Poll
The State of Ransomware
The State of Ransomware
Ransomware has become one of the most prevalent new cybersecurity threats faced by today's enterprises. This new report from Dark Reading includes feedback from IT and IT security professionals about their organization's ransomware experiences, defense plans, and malware challenges. Find out what they had to say!
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2017-0290
Published: 2017-05-09
NScript in mpengine in Microsoft Malware Protection Engine with Engine Version before 1.1.13704.0, as used in Windows Defender and other products, allows remote attackers to execute arbitrary code or cause a denial of service (type confusion and application crash) via crafted JavaScript code within ...

CVE-2016-10369
Published: 2017-05-08
unixsocket.c in lxterminal through 0.3.0 insecurely uses /tmp for a socket file, allowing a local user to cause a denial of service (preventing terminal launch), or possibly have other impact (bypassing terminal access control).

CVE-2016-8202
Published: 2017-05-08
A privilege escalation vulnerability in Brocade Fibre Channel SAN products running Brocade Fabric OS (FOS) releases earlier than v7.4.1d and v8.0.1b could allow an authenticated attacker to elevate the privileges of user accounts accessing the system via command line interface. With affected version...

CVE-2016-8209
Published: 2017-05-08
Improper checks for unusual or exceptional conditions in Brocade NetIron 05.8.00 and later releases up to and including 06.1.00, when the Management Module is continuously scanned on port 22, may allow attackers to cause a denial of service (crash and reload) of the management module.

CVE-2017-0890
Published: 2017-05-08
Nextcloud Server before 11.0.3 is vulnerable to an inadequate escaping leading to a XSS vulnerability in the search module. To be exploitable a user has to write or paste malicious content into the search dialogue.