Tricking users into visiting a malicious webpage could allow malicious people to compromise 150 models of HP multi-function printers, according to F-Secure researchers.
The Finland-headquartered infosec firm said it had found “exploitable” flaws in the HP printers that allowed attackers to “seize control of vulnerable devices, steal information, and further infiltrate networks in pursuit of other objectives such as stealing or changing other data” – and, inevitably, “spreading ransomware.”
“In all likelihood, a lot of companies are using these vulnerable devices,” said F-Secure researchers Alexander Bolshev and Timo Hirvonen.
“To make matters worse, many organizations don’t treat printers like other types of endpoints. That means IT and security teams forget about these devices’ basic security hygiene, such as installing updates.”
Tricking a user into visiting a malicious website could, so F-Secure said, result in what the infosec biz described as a “cross-site printing attack.”
The heart of the attack is in the document printed from the malicious site: it contained a “maliciously crafted font” that gave the attacker code execution privileges on the multi-function printer.
The vulns were publicly disclosed a month ago. The font vulnerability is tracked as CVE-2021-39238 and is listed as affecting HP Enterprise LaserJet, LaserJet Managed, Enterprise PageWide, and PageWide Managed product lines. It is rated as 9.3 out of 10 on the CVSS 3.0 severity scale.
F-Secure advised putting MFPs inside a separate, firewalled VLAN as well as adding physical security controls including anti-tamper stickers and CCTV.
Updated firmware is available for download from HP, the company said in a statement.