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RSA Encryption Key Vulnerability

Due to a vulnerability in the chipsets that are used to generate RSA encryption keys, the security of stored passwords, encrypted disks and documents have been weakened.
Threat ID:
CC-1706
Category:
Exploit
Threat Severity:
Medium
Threat Vector:
Published:
18 October 2017 12:00 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

This content has been archived

This article no longer conforms to NHS Digital's standards for cyber alerts, and may contain outdated or inaccurate information. Use of this information contained in this page is at your own risk

Summary

Due to a vulnerability in the chipsets that are used to generate RSA encryption keys, the security of stored passwords, encrypted disks and documents have been weakened.

Threat details

The flaw has been found in cryptographic smartcards, security tokens, chipsets and secure hardware manufactured by German semiconductor firm Infineon Technologies.

The Return of the Coppersmith's Attack (ROCA) vulnerability, CVE-2017-15361, relates to the Trusted Platform Module (TPM) used to cryptographically sign and protect computer systems and services. The bug was discovered within the implementation of RSA keypair generation in a cryptographic library, allowing what is called a "practical factorisation attack." This attack type permits an attacker to use a target's public key to generate a private key with some time and power. The attack is possible for common key lengths, including 1024 and 2048 bits.

Infineon's cryptographic chips and TPMs are also integrated within authentication, signature and encryption tokens of other vendors and chips. Google Chromebooks, HP, Lenovo and Fujitsu PCs and laptops, alongside routers and other devices have been affected.

It is important to note that RSA algorithms are not at fault here, but rather buggy products which mean the implementation of the security algorithm does not happen correctly and are not truly randomized. There are tools that you can use to test the RSa public keys against this flaw.

Remediation steps

Type Step
  • Users and administrators are encouraged to apply the necessary updates. HP, Google, Microsoft, Lenovo and Fuitsu have patches available.
  • Increase the key lengths to be more than 2048 bits
  • If a sensitive device cannot be patched, consider replacing the device.

Last edited: 17 February 2020 11:38 am