A free implementation of SSH and Telnet for Windows and Unix platforms, along with an xterm terminal emulator.
PuTTY is a client program for the SSH, Telnet, Rlogin, and SUPDUP network protocols.
These protocols are all used to run a remote session on a computer, over a network. PuTTY implements the client end of that session: the end at which the session is displayed, rather than the end at which it runs.
In really simple terms: you run PuTTY on a Windows machine, and tell it to connect to (for example) a Unix machine. PuTTY opens a window. Then, anything you type into that window is sent straight to the Unix machine, and everything the Unix machine sends back is displayed in the window. So you can work on the Unix machine as if you were sitting at its console, while actually sitting somewhere else.
Security issue: fixed a remotely triggerable double-free in RSA key exchange. (We don't know of any way it is exploitable to execute code.)
Minor security issue: fixed a remotely triggerable crash in NIST ECDSA signature verification. (An assertion failure – definitely not exploitable to execute code.)
Minor security issue: fixed marking of Telnet and Rlogin session data with a trust sigil after you authenticated to a proxy (possibly allowing a server to spoof a repeat proxy password prompt).
Ability to run a specified command before starting the connection, e.g. to perform wake-on-LAN or a port knock.
On Unix: display 'pre-edit text', showing the progress of using multiple keystrokes to compose a single Unicode character.
On Unix: improved support for to running the GUI tools on Wayland (fixed startup issues and tuned performance).
Bug fix: configuring a SSH certificate authority on Unix would fail unless you manually made a config directory.
Bug fix: spurious "Network error: Socket is not connected" when authenticating to some HTTP proxies.
Bug fix: disabling cursor blinking in the Windows Control Panel but enabling it in PuTTY would lead to a tight loop.
