For the first time, researchers have demonstrated that a large portion of cryptographic keys used to protect data in computer-to-server SSH traffic are vulnerable to complete compromise when naturally occurring computational errors occur while the connection is being established.

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The vulnerability occurs when there are errors during the signature generation that takes place when a client and server are establishing a connection. It affects only keys using the RSA cryptographic algorithm, which the researchers found in roughly a third of the SSH signatures they examined. That translates to roughly 1 billion signatures out of the 3.2 billion signatures examined. Of the roughly 1 billion RSA signatures, about one in a million exposed the private key of the host...

This raises the possibility that the leaked key could push out updates that would infect a computer’s most nether regions without triggering a warning. To make matters worse, Matrosov said, MSI doesn’t have an automated patching process the way Dell, HP, and many larger hardware makers do. Consequently, MSI doesn’t provide the same kind of key revocation capabilities.

Delivering a signed payload isn’t as easy as all that. “Gaining the kind of control required to compromise a software build system is generally a non-trivial event that requires a great deal of skill and possibly some luck.” But it just got a whole lot easier...

The vulnerability, which Oracle patched on Tuesday, affects the company’s implementation of the Elliptic Curve Digital Signature Algorithm in Java versions 15 and above. ECDSA is an algorithm that uses the principles of elliptic curve cryptography to authenticate messages digitally.

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ECDSA signatures rely on a pseudo-random number, typically notated as K, that’s used to derive two additional numbers, R and S. To verify a signature as valid, a party must check the equation involving R and S, the signer’s public key, and a cryptographic hash of the message. When both sides of the equation are equal, the signature is valid. ...