Hi,
I'm having the same issue. My son has a MacBook with parental controls on his account. The rdrcef app has been given permission to run in the parental controls setup. Still, when he logs in and accesses pdf files on some web pages, we get this error repeatedly, even when we enter administrator passwords to allow it once or always. The link to "how to stop Adobe CEF helper" was not helpful. It's over a year old and refers mostly to people running Windows and/or Creative Cloud. This computer has neither, just the latest version of Adobe Reader on a MacBook with Yosemite.
Thanks for your help.