Does the Product Store ANE access the UDID?

My app keeps getting rejected because apparently the UDID is being accessed somewhere. They won't give specifics so i'm trying to narrow it down. I'm only using 3 extensions. the Product Store, a social extension and a MoPub. (I have updated the MoPub to the recent update which supposedly doesn't access the UDID so)

Email received:

We have discovered one or more issues with your recent delivery for "Tweaked Revolution". To process your delivery, the following issues must be corrected:

Non-public API usage:

• Apps are not permitted to access the UDID and must not use the uniqueIdentifier method of UIDevice. Please update your apps and servers to associate users with the Vendor or Advertising identifiers introduced in iOS 6.

If method names in your source code match the private Apple APIs listed above, altering your method names will help prevent this app from being flagged in future submissions. In addition, note that one or more of the above APIs may be located in a static library that was included with your app. If so, they must be removed.