Is this spider dangerous

I am not sure ... but that depends on the species:

Araneus was originally called Epeira.

Araneus Spiders possess various venom's, but will deliver a dry bite on 8 out of 10 occasions. Females bite more often than males, who would rather flee or feign death.

Araneus diadematus

Since this tends to be a passive animal, it is difficult to provoke to bite---but if it does, the bite is just slightly unpleasant and completely harmless to humans.

But because there are more species the pain may be diferent:

One Bite Report:

- On the arm it can swelled badly for 3 days. And you may fell nausea's after a bite.

Also known as Orb-Weaving Spiders their venon is of low risk (not toxic) to humans. They are a non-aggressive group of spiders. Seldom bite. Be careful not to walk into their webs at night - the fright of this spider crawling over one's face can be terrifying and may cause a heart attack, particularly to the susceptible over 40 year olds.

(from wikipedia, Natural History Museum and USA Spider Identification Chart)