It is unfortunate that some vendors push bad security practices.
The JDK 7 update 55 is showing "This update is locked with a password." popup.
It is obvious that you would not give your password to any stranger asking it on the street, and this prompt is no different from a stranger. You have no way of telling where that password will be used.
It is a good practice to use system services for transparent and trusted way to ask for additional privileges. This update clearly violates this principle.
Below is a screenshot displaying the popup along with plausible ps axu listing showing that it might indeed be Oracle's update prompting for some password.
Shame on Oracle for making phishing user credentials one step easier.
https://www.dropbox.com/s/znoavsap0dv9ruw/Screenshot%202014-04-22%2019.15.53.png
Agreed, this just happened as I was updating it. What is even more disturbing is its now nearly May and people have been coming across this issue since last year.
Appalling behaviour by a supposedly competent developer.