We understand that there is an issue circulating around the permissibility of Cadbury products. This is something that arises every now and then and is linked to a false news story in Asia of several years ago.

AFIC Halal Authority certifies Cadbury products manufacture...

This article from the Halal Development Corporation gives a good summary of the difference of opinion in relation to vinegar and its permissibility.  AHA takes the position mentioned in the article of the Malaysian Fatwa Committee.

HDC Explanation of the permissibility...

In this section of our website we will provide general information on important issues relating to Halal, who we do and don't certify and why and important notice for members of the community on halal products and certification.  Follow this section to keep up to date.