Software Update: PuTTY 0.64 Beta

A new release of PuTTY has become available and as usual it is offered as beta. PuTTY is one of the most popular telnet and ssh clients, which allows remote management of a computer over a secure connection. Originally, the program was only available for Windows, but today there are also clients for the various Unix platforms. The changelog for version 0.64 can be found below.

PuTTY 0.64 released, fixing SECURITY HOLES

PuTTY 0.64, released today, fixes a security hole in 0.63 and before: private-key-not-wiped-2† also diffie-hellman-range-check has been argued to be a security hole. In addition to these and other less critical bug fixes, 0.64 also supports the major new feature of sharing an SSH connection between multiple instances of PuTTY and its tools, and a command-line and config option to specify the expected host key(s).

These features are new in beta 0.64:

• Security fix: PuTTY no longer retains the private half of users’ keys in memory by mistake after authenticating with them. see private-key-not-wiped-2† (Sorry! We thought we’d fixed that in 0.63, but missed one.)
• Support for SSH connection sharing, so that multiple instances of PuTTY to the same host can share a single SSH connection instead of all having to log in independently.
• Command-line and configuration option to specify the expected host key(s).
• Defaults change: PuTTY now defaults to SSH-2 only, instead of its previous default of SSH-2 preferred.
• Local socket errors in port-forwarded connections are now recorded in the PuTTY Event Log.
• Bug fix: repeat key exchanges in the middle of an SSH session now never cause an annoying interactive host key prompt.
• Bug fix: reset the bolded-text default setting back to what it used to be. (0.63 set it to something wrong, as a side effect of refactoring.)
• Bug fix: IPv6 literals are handled sensibly throughout the suite, if you enclose them in square brackets to prevent the colons being mistaken for a :port suffix.
• Bug fix: IPv6 dynamic port forwardings should work again.