Check Point has discovered a new vulnerability in HP’s range of office fax machines that allow hackers to exploit a fax number related flaw and gain access to the remainder of the company’s enterprise network. This exploit is not limited to any one product or any particular company’s setup, but it encompasses all of HP’s office fax machines and all-in-one devices that have a faxing system integrated within them.
Check Point discovered this flaw by testing the HP Officejet all-in-one printer fax machines, but they’ve reported that the flaw is not device specific. The vulnerability comes out of the fax protocol that HP uses, making all of its fax ready machines vulnerable to exploit. This means that other singular fax machines, fax-to-mail services, and fax implementations are also vulnerable to this exploit according to Check Point’s conclusion.
The way this exploit works is that a hacker finds a way to gain access of a company’s fax machine and then laterally expand his or her control across the company’s network. Fax machines are the most open target points for attack as they can be accessed by anyone remotely. As the faxing mechanism does not carry out any particular filtration and allows for connections from anywhere without a least privilege implementation, hackers can exploit these connections to gain privileges to more parts of the network. These channels can be used to cause buffer or static overflows.
Although the world has moved towards a more digitized communication approach, fax machines still remain well integrated into the crux of offices all around the world. This means that hackers can use these platforms to gain access to systems and carry out just about any desired command from snooping through confidential information to stealing documents or mining Bitcoin.
HP has released an update for this compound vulnerability (CVE-2018-5925 and CVE-2018-5925, each with CVSS 3.0 base score of 9.8) on its website. HP fax integrated machine users are requested to update their devices accordingly. In addition to this, it is advised that companies employ least privileges on fax machine like devices and set them up on isolated network segments so that the remainder of the company’s network is not made vulnerable through this platform.