A vulnerability in Microsoft HyperTerminal due to a boundary error in the handling of session files and telnet URLs can cause a buffer overflow by tricking a user into opening a malicious HyperTerminal session file (.ht) or clicking a specially crafted telnet URL in a malicious e-mail or on a website.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/35342/hyperterm.txt
Source: https://packetstormsecurity.com/files/35342/hyperterm.txt.html