Unsurprising, and I don't think it's a backdoor like ME, but just plain incompetence (or malpractice). It's only a matter of time and location when a exploit like this is discovered. I highly recommend this hilarious paper, <i>Fuzzing the GSM Protocol</i> (<a href="https://www.ru.nl/publish/pages/769526/scriptie-brinio-final-brinio_hond.pdf" rel="nofollow">https://www.ru.nl/publish/pages/769526/scriptie-brinio-final...</a>). By feeding the phones with random GSM data with a Software-Defined Radio, it showed most dumb and smartphones have serious memory corruption issues. Just starts reading from Page 27, Chapter 5.<p>* Read Memory<p>> <i>On two different phones it was possible to read out (part of) the phone memory. The most interesting of these phones was the Nokia 2600, where a text message would get stored that shows a seemingly random part of the phone memory upon opening. Closing and reopening of the same message
would display a different part of the memory, sometimes also causing a reboot of the phone.</i><p>> <i>On the Samsung SGH-D500 certain messages would show a strange sequence
of characters when opened, but it was unclear to us where it came from. The same message would show up differently when sent multiple times, so we expect it came somewhere from memory.</i><p>* Reboot<p>> <i>Seven of the sixteen phones could be forced to reboot remotely. When rebooting the network connection would be lost temporarily.</i><p>> <i>In all but two cases reboots were caused by a discrepancy between a length field and the actual length of that field in the message, making it likely that the behaviour is caused by a buffer overflow.</i><p>* Long time DoS<p>> <i>For the iPhone 4 and HTC Legend the attack with the highest impact was found. By sending a carefully crafted SMS message the phone would not display anything and also stop receiving any SMS messages altogether. In addition on the iPhone it was impossible to change network after the attack.</i><p>* Icons<p>> <i>SMS offers the ability to notify a user that a voice, fax or email message is waiting to be retrieved. According to the specifications every cell phone has to show an icon on the screen when this happens. Problem is that these icons are hard to remove when they were activated illegitimately. Even though this is not an actual security risk it can be quite annoying.</i><p>(lol!)<p>* Unable to delete messages<p>> <i>A rather annoying bug manifested itself on two cell phones, the Sony Ericsson T630 and Samsung SGH-D500. [...] They could not be viewed or deleted in any way, but they still occupied space on the SIM. The only way to delete these messages was to put the SIM in a different phone and delete them there.</i><p>> <i>Problems like these can be quite dangerous.</i><p>Nowadays, it's an extremely dangerous problem in the age of smartphones, when the baseband processor contains proprietary, unauditable code, with no isolation between the baseband processor and the main system.