Backdoored firmware lets China state hackers control routers with “magic packets”::The modified firmware used by BlackTech is hard to detect.
In an advisory of its own, Cisco said the threat actors are compromising the devices after acquiring administrative credentials and that there’s no indication they are exploiting vulnerabilities.
If they aren’t exploiting vulnerabilities (and this is all because of mishandling of admin creds) then why are only Cisco routers being targeted?
homesweethomeMrL@lemmy.world 1 year ago
Cisco also said that the hacker’s ability to install malicious firmware exists only for older company products. Newer ones are equipped with secure boot capabilities that prevent them from running unauthorized firmware, the company said.
To install their modified bootloader, the US and Japanese advisory said, the threat actors install an older version of the legitimate firmware and then modify it as it runs in memory. The technique overrides signature checks in the Cisco ROM monitor signature validation functions, specifically functions of Cisco’s IOS Image Load test and the Field Upgradeable ROMMON Integrity test. The modified firmware, which consists of a Cisco IOS loader that installs an embedded IOS image, allows the compromised routers to make connections over SSH without being recorded in event logs.