CRIME (security exploit) – Wikipedia, the free encyclopedia
from http://tech.slashdot.org/story/13/07/09/1455200/ It works like this. You visit a site that has malicious JavaScript which sends a HTTPS request to some site (like your bank). This request will include whatever known plain-text that the JavaScript wants to send, *plus* any cookies you have stored for the target site, possibly including authentication cookies. If the plain text happens to match part of that authentication cookie, then the compressed headers will be smaller than if they if they don't match. If the attacker can monitor this encrypted traffic and see the sizes of the packets, then they can systematically select the known plaintext to slowly learn the value of the authentication cookie. This can be done today in about half an hour. And the attack setup is feasible - consider a public WiFi access point that requires you to keep a frame open in order to use their WiFi. This gives them both the MITM and JavaScript access needed to perfo...