Hackers can reset your phone via SMS, Facebook, or Windows Live Messenger communications.
Some of you may have fond memories of "nuking" local Windows 95 machines using urgent pointer (URG) based TCP "winnuke" tools (e.g. "NukeIt") or Windows 98 machines via large fragmented IGMP packets with malformed headers. Now Microsoft's Windows Phone has become the latest in a long line of Microsoft Corp. (MSFT) operating systems to be "hosed" by malicious traffic.
The flaw in Windows Phone, which affects the latest build of Windows Phone 7.5 Mango, as well as previous versions, was first discovered by Windows Phone hacker Khaled Salameh. Rather than following in the tradition of hackers of yore, he worked with the site WinRumors to report the bug and securely disclose it to Microsoft.
The flaw appears to affect all Windows Phones, regardless of the manufacturer or model.
The attack works by sending a message to the Windows Phone message hub application. As this app accepts a variety of messages, the attacking message can be in the form of a SMS text message, a Facebook message, or a Windows Live Messenger hub.
When the message is received, errors in the handling in the hub cause the message to lock the device, killing whatever work you had in process. You can recover via a reboot.
However, your message hub app will stay dead. It is unclear if there is a fix for restoring messaging functionality, but barring a reformat of your device, the affected phone may be unable to message. Worse yet, if you have a live tile from the contact that sent the message, once it updates post-reboot it will trigger another system lock-up. There is a workaround for this -- quickly navigate to the homescreen and remove/unpin the tile before it "flips" (updates).
For now, as mentioned, this severe vulnerability's implementation details are under wraps, pending a fix, so Windows Phone users should only be mildly concerned.
Again, this vulnerability appears to be solely capable of denial of service, and does not affect your system security. In that regard it appears to be very similar to the aforementioned "winnuke" attacks, or the more recent "SMS-o-Death" messaging attack demoed against Android and iOS by researchers Collin Mulliner, a PhD student in the Security in Telecommunications department at the Technische Universitaet Berlin, and Nico Golde, an undergraduate student at the same institution.
These attacks differ from security-breach attacks, like the SMS attack that affected older unpatched version of iOS, first discovered by Charlie Miller. The key difference is that those kinds of attacks utilize flaws in messaging apps which allow the execution of arbitrary code as a path to root control; where as attacks like the one in this article exploit flaws in message handling which do not execute arbitrary code, but do trigger some sort of catastrophic system failure.