End-of-life enterprise routers are often not reset to factory settings before being recycled or resold. And since network equipment can accumulate a lot of secrets about the organization during its operation, this issue cannot be ignored. Competent hackers will be able to use any at least somewhat useful information to organize a targeted attack on the former owners of the equipment.
ESET recently purchased 18 used enterprise routers from Cisco, Fortinet and Juniper Networks for research purposes from several very different companies. Slovak experts found that 9 devices contained complete network configuration data, 4 more contained only part of the useful data, but could still be used by attackers, and only the remaining 5 devices were properly reset.
In the case of nine particularly vulnerable routers, based on the data present on the devices, experts were able to determine with a high degree of certainty which specific companies were the previous owners of network equipment.
Confidential but easily accessible corporate information found on these routers included IPSec and VPN credentials, credentials for connecting to other networks, hashed passwords, authentication keys, information about all clients ever connected to the router, credentials for accessing cloud applications, firewall rules and other information that allows third parties to freely connect to the corporate network of the victim company.
“With this level of detail, it would be much easier for an attacker to impersonate network or internal hosts, especially since such devices often contain VPN credentials or other easily hacked authentication tokens,” ESET explained.
Another important piece of information received from the routers was related to the organization's overall security level. It is easy for an attacker to determine by the configuration of network equipment whether company employees bother about security in principle, or everything is open.
ESET even tried to contact the previous owners of the tested routers to warn them of the potential risk. Several organizations have completely ignored the company, and in one they announced a contract with a specialized equipment disposal service, which, apparently, did not comply with the necessary safety procedures and standards for a long time. Of course, for representatives of the affected organization, this news was shocking.
The researchers also explained that simply resetting a router or other network equipment to factory settings would be enough to prevent attackers from using the device to compromise a live network. In this regard, such a simple and quick action is clearly not worth neglecting. Moreover, most router models can be easily reset even without connecting to a computer, you just need to hold the RESET button on the device case for a while.