How secure is Google Chrome's password-saving functionality? I learned that it saves passwords to a file and a database in which all the passwords are encrypted. In particular, I would like to know if Chrome is the only application that can decrypt it, or if any person or application can grab the plaintext password once the encrypted password is stored on the computer.
Is Chrome is the only application that can decrypt it's saved passwords?
No. There is a least one program that I know of that will display the passwords.
WebBrowserPassView is a password recovery tool that reveals the passwords stored by the following Web browsers: Internet Explorer (Version 4.0 - 11.0), Mozilla Firefox (All Versions), Google Chrome, Safari, and Opera. This tool can be used to recover your lost/forgotten password of any Website, including popular Web sites, like Facebook, Yahoo, Google, and GMail, as long as the password is stored by your Web Browser.
There are probably others.
The browser's password-saving mechanism is a weak and insecure tool, for all browsers, although it's perhaps better than nothing.
It's better to use a cloud-based encrypted product that will be completely secure, even in case of catastrophic failures like losing your hard disk, and available on more than one device. Such products usually come in both desktop and browser-extension formats.