The scenario you describe is absolutely possible. But this is not an issue with cards but with how you protect the credential (the certificate in your case).
Either -
a) you should not leave you machine unlocked
b) you cert is on a smart card that requires a PIN
c) you use strong private key protection which requires a PIN equivalent for soft certs
and btw - your scenario would also work without cards - e.g. when the web site would require a SSL client cert (and you use an unprotected soft cert).
Dominick Baier |
thinktecture |
http://www.leastprivilege.com