WinSCP - URI Handler Command Switch Parsing

About winscp :

WinSCP is an open source freeware SFTP client for Windows using SSH.
Legacy SCP protocol is also supported. Its main function is safe copying
of files between a local and a remote computer.

Versions affected :

It was tested on WinSCP 3.8.1 , previous versions may or may not be
affected

Description :

During a typical installation of winscp several URI handlers are
installed. (scp:// sftp://) It is possible to include additional command 
line switches to be passed to winscp

Some of these switches may initiate  a file transfer, sending a
specified file to an arbitrary ftp. or they may download executables to
a location on a pc where they would be executed. eg. the startup folder

If you create an html page with these contents

download malware.exe

And click on the link it would automatically download malware.exe to a
c:\ (asuming the host is in the cache otherwise user interaction is
required)

clicking on

href="scp://jelmer@127.0.0.1:22/%22%20%22/log=c:%5csomefile% 
22"log

would append log output to c:\somefile possibly rendering the file
unusable in the process. Note that this also works when the host is not
in the cache

Vendor status :

Martin Prikryl was notified June 04, 2006, He will "think about a
solution"