Using the clipboard at all for security related things like temporarily storing a password is a bad idea. The clipboard is a big public billboard visible to anything running on your computer.
The fact that password managers use it at all is simply because it is the only hack that works to reliably get data into password boxes. Yes, its a hack. The HTML5 spec should have exposed a mechanism to securely insert data into an element tagged for such a purpose. A one way mechanism.
The fact that password managers use it at all is simply because it is the only hack that works to reliably get data into password boxes. Yes, its a hack. The HTML5 spec should have exposed a mechanism to securely insert data into an element tagged for such a purpose. A one way mechanism.