Question about plugins labeled as open source but looks like another plugin

First, excuse the rookie question. I don’t know where to ask this question.
Background: I’ve used a plugin (Plugin A) that was removed from the plugin repository due to security reasons.
I found another plugin (Plugin B) to replace it in the plugin repository, but I noticed that the replacement plugins (Plugin B) back-end looked very similar to Plugin A’s. So I downloaded it. I compared both plugins main php file and they are exactly the same in wording except the name of the plugin was swapped out. And Plugin B has an additional function located at the bottom of the page.
— Both plugins have the same dashboard GUI except for the author links.
— Both plugins state that they are “open source software” but contain a copyright in the comments.
So I am a bit confused…
QUESTION 1: Can someone copy a plugin’s code almost verbatim and have it available in the plugin repository and call it something else?
QUESTION 2: If Plugin A was not available for download due to a Security Issue, what makes me think that Plugin B is any safer? I’m not a coder.
QUESTION 3: Are plugins checked for quality control?

Thanks for your time and input.

• This topic was modified 4 years ago by Kevin.