PuTTY0.85.0.0

Use PuTTY to open a remote computer session in a window on your Windows machine and work with that system from a distance. Characters typed into the terminal are sent across the network, while the remote computer’s responses appear in the same window. This gives administrators, developers, and Unix users direct command-line access without being physically present at the other machine’s console.

PuTTY supports SSH, Telnet, Rlogin, and SUPDUP connections, handling the client side of each protocol. It also provides an xterm terminal emulator, so text-based programs running on the remote system can be used through a familiar terminal interface.

Version 0.85.0.0 fixes a remotely triggerable use-after-free in Pageant that might permit code execution, although code execution has not been proven. It also corrects a remotely triggerable buffer overflow when OpenSSH encrypt-then-MAC modes are used, though those modes apply only when the server supports no alternative, and fixes a private-key decryption overflow involving a maliciously constructed key that can be triggered deliberately only if someone else is allowed to generate the key.

The release further addresses denial-of-service issues in which a server can force PuTTY into a tight loop or a man-in-the-middle attacker can cause unlimited memory consumption during startup. These capabilities make PuTTY useful for remote administration, network-based development, and routine access to Unix-like systems from a Windows workstation.