There is a new bug that iPhone users have to watch out for. People who have updated to iOS 11.2.5 are the only ones who will face this bug. A character from Indian language is sent to your phone which then crashes the phone when you try to open it. The specific character belongs to Telugu language. Once received, the phone tries to read it again and again and keeps crashing in the process hence rendering the phone useless.
There is no definite solution to fix this bug. The only chance you have is to ask someone to send you a normal text message in order to open the messaging app. You can then delete the thread with the faulty character.
This version of of iOS was developed in order to support the HomePod. If you own a HomePod then your phone is definitely vulnerable to this bug. We hope Apple sends us a fix soon. There have been too many bugs lately and Apple needs to get its act straight.