Microsoft says it is working on Windows Phone SMS fix

The revelation that a major flaw in the SMS features of Windows Phone-based devices hit the Internet earlier this week. Late on Tuesday, Microsoft finally issued a statement to The Verge about the issue.

The article quotes Greg Sullivan, the senior product manager for the Windows Phone division at Microsoft, as saying, "We are aware of the issue and our engineering teams are examining it now. Once we have more details, we will take appropriate action to help ensure customers are protected."

Just to recap, the flaw is in the Windows Phone 7.5 (or "Mango") operating system. If someone discovered the exploit, they could use it to disrupt a Windows Phone device via a SMS-based attack.

So far there's been no details about how exactly this SMS flaw works to disable Windows Phone. It also doesn't appear to affect any security features. However, it's still an annoyance and clearly a issue that Microsoft can and should fix quickly via either an over-the-air update to Windows Phone 7.5 or an update that requires connecting the Windows Phone device to a PC and downloading the fix via the Zune software.

Report a problem with article
Previous Story

Lumia 800 gets Dark Knight Rises special edition

Next Story

Lumia 710 gets official on US T-Mobile

15 Comments

"So far there's been no details about how exactly this SMS flaw works to disable Windows Phone."

The details are it causes the messaging app to crash whilst parsing a very long and obscure string inside a message - ergo the messaging app won't open properly (it'll just crash everytime you try to launch it), and everything else on the phone works fine

As long as it doesn't make its way public for the next month or so we should all be dandy.

~Johnny said,
"So far there's been no details about how exactly this SMS flaw works to disable Windows Phone."

The details are it causes the messaging app to crash whilst parsing a very long and obscure string inside a message - ergo the messaging app won't open properly (it'll just crash everytime you try to launch it), and everything else on the phone works fine

As long as it doesn't make its way public for the next month or so we should all be dandy.

Actually, if you get hit through Facebook and it ends up on your Live Tiles, it can lock up the whole phone.

THolman said,
Actually, if you get hit through Facebook and it ends up on your Live Tiles, it can lock up the whole phone.

Whelp, more reason to hope it doesn't make it beyond the two / few people outside of Microsoft who know about it =P.
Though in either case, there's certainly *some details* about how it does it, not none

It's worth noting that it's not actually a Windows Phone specific bug either - the same string can crash many other Microsoft programs on the desktop (Visual Studio, Blend, Help, WLM 2011, etc), which would lead me to believe there is some extremely obscure problem with Microsoft's general string parser somewhere.

~Johnny said,

It's worth noting that it's not actually a Windows Phone specific bug either - the same string can crash many other Microsoft programs on the desktop (Visual Studio, Blend, Help, WLM 2011, etc), which would lead me to believe there is some extremely obscure problem with Microsoft's general string parser somewhere.

Where did you hear or read that?

link8506 said,

Where did you hear or read that?

From the Twitter account of the guy who originally found the issue. Of course, winrumours who broke the story failed to mention this at any point, and ergo no one else who have picked up the story from them have done so either =P (I'm on a phone at the mo, so you'll have to browse for the link)

~Johnny said,

As long as it doesn't make its way public for the next month or so we should all be dandy.

Even it is made public, it's not that bad.

It's NOT a major flaw since there is no proof it could lead to some remote code execution (as opposite to similar SMS flaws affecting ios/symbian/android in the past, and still affecting old android devices not updated by the manufacturer)

Also, don't forget that almost every feature phone have this kind of flaw and they never get patched. Mass sending of Sms is not free, even with an unlimited sms plan you are limited to 200 different recipients par month. That's why there has never been any mass DoS against devices affected by this kind of flaw.

So, there is no reason to worry, and I don't expect MS to release a patch until several months, even if the exploit becomes public.

~Johnny said,

From the Twitter account of the guy who originally found the issue. Of course, winrumours who broke the story failed to mention this at any point, and ergo no one else who have picked up the story from them have done so either =P (I'm on a phone at the mo, so you'll have to browse for the link)

I hope it just causes an unexploitable crash then!
If it is a flaw in a string library it may be serious.
If it is a flaw in a text rendering graphic library it's not that bad.

link8506 said,
It's NOT a major flaw since there is no proof it could lead to some remote code execution (as opposite to similar SMS flaws affecting ios/symbian/android in the past, and still affecting old android devices not updated by the manufacturer)

...

So, there is no reason to worry, and I don't expect MS to release a patch until several months, even if the exploit becomes public.

As true as the rest of that may be, this is a major flaw considering that it could be used to break your entire phone.

One of the beauties of WP7 is that its messaging and people hubs are highly extensible, and internally they clearly and intelligently share a lot of the same code. Unfortunately, that also means that any flaw in that library is exposed through each facet.

That means, as has been pointed out, every time you receive a toast notification with the text, then your phone crashes and it must be restarted. Every time that text flips onto the face of a Live Tile, then your phone crashes and it must be restarted. Any time that that text appears in a message, then your message hub is unopenable because it simply crashes on-load. Use Twitter? Definitely going to crash as long as the message is under the character limit. I am curious if email has trouble with it; considering that it uses the same smileys available to messaging, then I expect the answer to be yes.

It would not take long before someone began trolling everything that they could to get the message to you, somehow. Sure, it might not be an SMS message because that might cost someone money, but it would become a serious issue very quickly through the many mediums available.

And I say this as an owner of a Samsung Focus S that I bought off contract because I love WP7 so much. I will not be hanging onto an OS that leaves such a hole open, with such a large attack surface, even if the results are just a huge inconvenience (restarting/reformatting) to me rather than a more serious security issue (stolen data/running arbitrary code). Whether or not this leaks to the public, they had better have a patch for it within a month, or it will just be a matter of time before I open up a message to someone being "funny" and suddenly my phone is screwed up.

Edited by pickypg, Dec 14 2011, 8:56pm :

~Johnny said,
"So far there's been no details about how exactly this SMS flaw works to disable Windows Phone."

The details are it causes the messaging app to crash whilst parsing a very long and obscure string inside a message - ergo the messaging app won't open properly (it'll just crash everytime you try to launch it), and everything else on the phone works fine

As long as it doesn't make its way public for the next month or so we should all be dandy.

Carriers should be blocking this, as it is a specific malformation that ALSO exceeds SMS specifications.

Just like if a stalker was dialing your phone number 100 times a minute, the carrier should intervene.

From what I read it is a specific parsing flaw in how strings are handles by .NET, that overloads (not precise usage here) the reading of the line.


The good thing about this flaw, is that even by exploiting a low level code interpretive mechanism of the base platform runtime compiler, it demonstrates that .NET and Silverlight are not subject to injection and other mechanisms that malware would normally use this low level of access to gain security or run arbitrary code. Which is a +1 for the level of rigidity of security.

(And that isn't even counting the isolation mechanisms in WP7 that prevent Apps from touching other Apps even through API calls.)

Like the analogy I used before, it is like someone dialing your 1970s telephone 100 times a minute from an automated computer, and jamming your line.

I hop they fix the other bug at the same time. The one that causes the keyboard to disappear while you are typing. This is annoying.

A bit out of topic here but am I the only one who has problems receiving SMS pictures from other phones and carriers?

Mouettus said,
I hop they fix the other bug at the same time. The one that causes the keyboard to disappear while you are typing. This is annoying.

A bit out of topic here but am I the only one who has problems receiving SMS pictures from other phones and carriers?


No, you aren't. I also have issues sending/receiving pictures sometimes. Running the HTC Connection Setup app seemed to help a bit.

Mouettus said,
I hop they fix the other bug at the same time. The one that causes the keyboard to disappear while you are typing. This is annoying.

A bit out of topic here but am I the only one who has problems receiving SMS pictures from other phones and carriers?

Messages with media in them are called MMS's, not SMS.

Speaking of which, when will WP7 finally get full MMS support? It's pathetic, really.

I've been looking for some dark phrases/incantations from Harry Potter and see if any of those has some effect but not luck

Commenting is disabled on this article.