Product: FirstClass Desktop Client 7.1
Developer: SoftArc
URL: http://www.softarc.com/

Description: Users clicking on a maliciously crafted link will result in 
local file execution.

Details:
FirstClass RTF formatted messages can include hyper-links to web URL's. 
When the messages recipient clicks on the URL the web browser is launched 
and navigates to the links URL. Crafting a malicious link is as simple as 
typing the local filename into the URL field of the form.

The most effective exploit would be to execute logoff.exe, forcefully 
terminating all running processes and logging the user out of their account.

C:\WINDOWS\SYSTEM32\LOGOFF.EXE

I wanted to mess with this further, but don't have time.

Also note that other protocols can be used to launch their associated 
software.

For example, hcp:// would launch the Windows help control panel, 
telnet://.... you get the idea.

Goodnight,
  Richard Maudsley

http://www.mindblock.org/
Greetings: Windsor Boys School
Matt & Dave: nice job on the network.
Greetings: French, Garlic, Shiva -- WBS Security Crew ;)