In coturn before version 220.127.116.11, there is an issue whereby STUN/TURN response buffer is not initialized properly. There is a leak of information between different client connections. One client (an attacker) could use their connection to intelligently query coturn to get interesting bytes in the padding bytes from the connection of another client. This has been fixed in 18.104.22.168.
Multiple memory corruption issues were addressed with improved memory handling. This issue affected versions prior to iOS 12.1, watchOS 5.1, Safari 12.0.1, iTunes 12.9.1, iCloud for Windows 7.8.