bob123 , as far I know in order to hacker can get a chance to steal coins from any Electrum before version 3.0.5 victim need to have open browser and run in a site where hacker is waiting his chance/of course victim need to have Electrum open/decrypted to make the hack successful. So in theory with no open browser older version are safe from this attack?
Well,
in theory, an opened malicious browser site is
one way to get a (non-encrypted) wallet compromised.
An attacker could also use a vulnerability of your OS or any service which run on your machine/network to get access to the RPC interface.
So, no. An open browser is not the only possiblity to get your funds stolen trough this vulnerability.
But, on the other hand, if your wallet is (properly) encrypted and the attacker does not have access to your password (e.g. via keylogger), your wallet
should be safe.
But this also means, that the moment you want to use your wallet (decrypting it), an attacker could exploit this vulnerability to steal your private keys.
So, storing an (properly) encrypted wallet should be fine. But you shouldn't use it (send funds / sign messages) if you want to stay safe.
The best way is to
always fix any issues and updating to the latest version.