Bugg i OpenSSH

En ny version av OpenSSH släpptes för några dagar sedan då det visade sig att minne läckte ut i certifikat:

When generating legacy *-cert-v00@openssh.com certificates, the nonce field was not being correctly filled with random data but was left uninitialised, containing the contents of the stack. The contents of the stack at this point in ssh-keygen’s execution do not appear to leak the CA private key or other sensitive data, but this possibility cannot be excluded on all platforms and library versions.

If certificates are generated using user-specified contents (as opposed to the CA specifying all fields) then they will be less resistant to hash collision attacks. Fortunately, such attacks are not currently considered practical for the SHA family of hashes used to sign these certificates.