Every version of the PuTTY tools from 0.68 to 0.80 inclusive has a critical vulnerability in the code that generates signatures from ECDSA private keys. Tthe effect of the vulnerability is to compromise the private key https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-p521-bias.html #infosec #security #ssh #opensource #linux #unix #windows