What is the feminist criticism of Cinderella?
A lot of people note that the Disney version of Cinderella, at least, is unfeminist because Cinderella is a passive entity in the execution of her own fate. Take away the mice and fairy godmother, and you'll notice that Cinderella does just about nothing to improve her situation, and executes exactly none of the critical actions of the film. She wishes for something, and others give it to her.
For example, lets take a look at those critical turning points in the film. You'll notice that the mice design her dress for her. Her godmother gives her a carriage and a new dress when her sisters destroy the first. The mice let her out of her room when her stepmother locks her away, and the prince whisks her away from her place of servitude. Cinderella herself, meanwhile, does little more than lament her situation and wish for someone to rescue her.
Princesses from the Disney canon that are seen as more feminist (though interpretations vary on just how feminist they really are) are those that exercise agency. In Beauty and the Beast, for instance, Belle's life is shaped by her own decisions--to take her father's place in the beast's castle, to go where she is forbidden to go, to leave the beast's castle and to return as she sees fit. Jasmine is another example: though Aladdin is ultimately the one who saves the day, the difference is that Jasmine executes many critical actions on her own.
One last, even more modern example is Disney's version of Rapunzel. Contrast the actions of Cinderella with those in the Rapunzel clip linked below, and see which appears to be more feminist.