An iOS hacker on his blog pod2g has mentioned that iPhone is vulnerable to a bug that allows text messaging spoofing. How does it happen? He explains that all sms information is converted into a format called Protocol Description Unit (PDU). This PDU then further delivers the sms to destined number using an information type User Data Header (UDH). Now it is the UDH which allows the user to change the reply address of the message. So the recipient is not able to see the original phone number and can’t make out whether the sms is spoofed or not.
This issue can allow the pirates and scumbugs to ask for private information by directing people to phishing wesbites of trusted companies like bank. Or someone can use this bug to create false evidences, manipulate people or simply play pranks.
So if you have a iPhone or any other handset that is UDH compatible, you can be tricked into text messages spoofing. Hence it is in your best interest that you avoid answering to the numbers which request for your personal logins or confidential information.
But never trust your text messages blindly!