4.1 million web hosts are exposing HTTPS and SSH traffic

Some 9% of all HTTPS web hosts and more than 6% of all SSH hosts on the web are vulnerable to private key attacks, according to a Sec Consult blog post.

The researchers analyzed cryptographic keys found in the firmware of more than 4,000 connected devices from more than 70 vendors. By correlating data with information from internet-wide scan tools – Scans.io and Censys.io – they’ve uncovered 580 actively-used keys.

900 devices – including internet gateways, routers, modems, IP cameras, network storage devices, mobile and Internet-connected phones – embedded private encryption keys in their firmware. Also, a significant number of the keys were shared across systems. The list includes Cisco, General Electric GE -0.86%, Huawei, Motorola and Seagate.

Source: Sec Consult

That’s because vendors may have shared the faulty code, selling it under white-label devices produced by different vendors (OEM, ODM products) or software development kits (SDKs). An example:

A certificate issued to a “Daniel”, email (kiding[at]broadcom.com) is used in firmware from Actiontec, Aztech, Comtrend, Innatech, Linksys, Smart RG, Zhone and ZyXEL. This certificate is found in a Broadcom SDK. The affected vendors used it as a basis to develop their own firmware. More than 480.000 devices on the web are using this single certificate.

Why is this a problem?

The private keys were “baked” into the operating system of the device and were mainly used to provide secure HTTPS and SSH access to the device.

If a hacker has access to the keys, he can impersonate the device. He can create a version of the target machine’s encryption certificate and sign it with that key. Then, he could deliver malware under a fake update notification from the server, request user credentials or simply spy on users’ sensitive information.

A ‘normal’ attacker would usually search for a specific target and then analyse this firmware for specific flaws or extract the private keys out of the firmware,” said Johannes Greil, head of SEC Consult Vulnerability Lab.

Unfortunately, end users are powerless in this case. To avoid future vulnerabilities, vendors should construct products that use random, unique cryptographic keys and test devices thoroughly before releasing them on the market.