Trusted platform module (TPM) chipsets from German semiconductor specialist Infineon have been found to create weak RSA key information that increases the threat of attack. TPM is a global standard for cryptoprocessors that helps companies securely store sensitive information, including passwords, certificates and encryption keys. TPM chipsets are included in the motherboards of many hardware manufacturers.
The researchers who discovered the threat are working with those hardware manufacturers and software vendors to help mitigate the risk. Until a fix is available, IT managers should take measures to protect users and then work with C-suite colleagues to raise the profile of information security.
How the RSA Key Vulnerability Works
Infineon issued a security alert detailing the vulnerability last week. The flaw results in the generation of insecure RSA keys and makes it theoretically possible for errant outsiders to attack RSA-1024 and RSA-2048, Bleeping Computer reported. It also gives attackers the opportunity to uncover the private key used in RSA encryption.
TPMs that rely on the TCG specification 1.2 and 2.0 are impacted. Firmware updates have been issued by Infineon.
TPMs are included in a range of devices, including laptops, routers and Internet of Things (IoT) technologies. Affected vendors include Acer, ASUS, Fujitsu, HP, Lenovo, LG, Samsung, Toshiba and a series of smaller Chromebook manufacturers, according to Bleeping Computer.
The Vendor Reaction
The vulnerability was uncovered by researchers from the Centre for Research on Cryptography and Security (CRoCS), who revealed the flaw to Infineon during the first week of February and agreed to delay public disclosure for eight months. In the meantime, they worked with manufacturers to help reduce the risk.
Infineon is just one of a series of TPM vendors, so the effects of the flaw do not spread across all motherboards. Impacted manufacturers have received the firmware update and are working to mitigate the potential threat. HP, Lenovo and Fujitsu have issued advisory notes that list affected products and are also pushing out firmware updates.
On the operating system side, Microsoft and Google also issued advisory notes that detail affected products. Both firms have created workarounds to help reduce the risk of attack, but full protection will rely on firmware updates from hardware vendors.
Understanding the Risk
The researchers who revealed the vulnerability suggested that the private key used in RSA encryption can be used to impersonate users, decrypt messages and forge signatures. The impact of the flaw is related to the usage scenario, availability of the public keys and the length of keys used.
The current number of known vulnerable RSA keys is about 760,000, according to CRoCS, but two or three times more keys could be at risk. The researchers will present further details of the threat at the upcoming ACM Conference on Computer and Communications Security in Dallas.
In the meantime, IT managers should move important users and data handling operations to devices unaffected by the flaw, according to Bleeping Computer. Once the firmware update is in place, security professionals should renew all TPM keys by altering passwords for TPM-enabled applications.