CORS error on version 0.40.0

[mercuryyy]

Failed to load http://prebid.adnxs.com/pbs/v1/openrtb2/auction: The value of the 'Access-Control-Allow-Origin' header in the response must not be the wildcard '*' when the request's credentials mode is 'include'. Origin 'http://www.mydomain.com' is therefore not allowed access. The credentials mode of requests initiated by the XMLHttpRequest is controlled by the withCredentials attribute.

Started at 1PM UST Time Aug 6

Please Advise we have 7 bidders on s2s got hit with a big revenue drop until we saw the error.

@dbemiller

[dbemiller]

Looks like this was caused by the cors library update: https://github.com/prebid/prebid-server/pull/637/files#diff-bd247e83efc3c45ae9e8c47233249f18R224

We rolled back our deployed version, and added some integration tests which run from a browser and make sure we get alerted sooner if it happens again.

Other PBS hosts should not use version 0.40.0. We'll fix this and release a 0.40.1 patch soon (sometime this week)