iPhone Security Issue Opens Door to SMS Spoofing

Jailbreak hacker and security researcher pod2g today revealed a newly-discovered security issue in all versions of iOS that could allow malicious parties to spoof SMS messages, making a recipient think that a message came from a trusted sender when it in fact came from the malicious party.

The issue is related to iOS's handling of User Data Header (UDH) information, an optional section of a text payload that allows users to specify certain information such as changing the reply-to number on a message to something other than the sending number. The iPhone's handling of this optional information could leave recipients open to targeted SMS spoofing attacks.

In the text payload, a section called UDH (User Data Header) is optional but defines lot of advanced features not all mobiles are compatible with. One of these options enables the user to change the reply address of the text. If the destination mobile is compatible with it, and if the receiver tries to answer to the text, he will not respond to the original number, but to the specified one.

Most carriers don't check this part of the message, which means one can write whatever he wants in this section : a special number like 911, or the number of somebody else.

In a good implementation of this feature, the receiver would see the original phone number and the reply-to one. On iPhone, when you see the message, it seems to come from the reply-to number, and you [lose] track of the origin.

pod2g highlights several ways in which malicious parties could take advantage of this flaw, including phishing attempts linking users to sites collecting personal information or spoofing messages for the purposes of creating false evidence or gaining a recipient's trust to enable further nefarious action.

In many cases the malicious party would need to know the name and number of a trusted contact of the recipient in order for their efforts to be effective, but the phishing example shows how malicious parties could cast broad nets hoping to snare users by pretending to be a common bank or other institution. But with the issue resulting in recipients being shown the reply-to address, an attack could be discovered or thwarted simply by replying to the message, as the return message would go to the familiar contact rather than the malicious one.

Top Rated Comments

(View all)
Avatar
104 months ago
I think we could use a slight rewrite of the article. It didn't say "malicious party" nearly often enough for me.
Score: 9 Votes (Like | Disagree)
Avatar
104 months ago



Nope. :apple:

But i'm not surprised it didn't come from someone legit.


Pod2g is quite legit in my book.
Score: 6 Votes (Like | Disagree)
Avatar
104 months ago
This makes no sense. You don't need to use UDH tricks to 'spoof' the sender ID on a text message, you just set whatever sender ID you want to use. Any text message can contain up to 16 digits or 11 alphanumeric characters of sender ID, and there's absolutely nothing that ensures this data is somehow verified or official.

Just as with an email you can, technically, originate it from wherever the hell you like, so can you with a text message.

This 'discovery' is not a discovery at all. In fact, it doesn't seem to be a problem at all. It would only be a problem if the sender ID displayed on the iPhone could be one thing, but the destination of the reply text messages could actually be something else that the user had no knowledge of. Correct me if I'm wrong, but in this instance the user is fully aware of the number they're texting. So no problem.

And yes, I know SMS.
Score: 6 Votes (Like | Disagree)
Avatar
104 months ago
Apple get you act together.

Uncle Ruckus no relations.
Score: 6 Votes (Like | Disagree)
Avatar
104 months ago

Agree with this. You are correct, this is not possible. When a reply-to address is specified iOS displays that and ignores the sender.

Yeah, I'm pretty sure this story is without merit and should be taken down. Simply a misunderstanding/lack of understanding about how SMS works.
Score: 5 Votes (Like | Disagree)
Avatar
104 months ago
It is easy to spoof caller ID and fool every phone on earth. How is this any more dangerous?
Score: 5 Votes (Like | Disagree)

Top Stories

Apple Confirms This Year's iPhone 12 Models Will Be a Little Bit Late

Thursday July 30, 2020 2:34 pm PDT by
During today's earnings call covering the third fiscal quarter of 2020 (second calendar quarter) Apple CFO Luca Maestri confirmed that Apple is expecting to release this year's iPhones later than usual. Maestri said that Apple last year started selling iPhones in late September, but this year, Apple projects supply will be "available a few weeks later." Multiple rumors have suggested that ...

Apple-Acquired Dark Sky Officially Shuts Down Android App

Saturday August 1, 2020 3:43 pm PDT by
Apple in March purchased weather app Dark Sky, and at that time, Dark Sky's developers said that the app's Android version would be discontinued on July 1, 2020. However, instead of shuttering the app on that date, the app's developers announced that the discontinuation would be delayed for another month. Now that it's August, Android users are no longer able to access the app, and...

Apple Watch Series 6 to Feature Blood Oxygen Monitoring Sensor

Friday July 31, 2020 1:56 am PDT by
The Apple Watch Series 6 will add blood oxygen monitoring to its features list when it's launched later this year, according to a new report from DigiTimes. Apple Watch 6 will feature biosensors that can monitor sleeping conditions, detect blood oxygen and measure pulse rates, heartbeats and atrial fibrillation, and will also incorporate MEMS-based accelerometer and gyroscope, all allowing the ...

Just How Small Will the 5.4-Inch iPhone 12 Screen Be? Try It Out for Yourself

Tuesday July 28, 2020 12:57 pm PDT by
As rumors of the iPhone 12 have continued to build over the past few months, the one model that has the most excitement around it is the smallest 5.4" model. The iPhone 12 is believed to be coming in 5.4", 6.7", and 6.1" sizes. Dummy models have shown how much smaller the 5.4" is compared to the rest of the iPhone lineup. The upcoming 5.4" iPhone falls in-between the size of the original...

Top Stories: Try the 5.4-Inch iPhone 12 Display Size, Blockbuster Earnings, Tim Cook at Antitrust Hearing

Saturday August 1, 2020 6:00 am PDT by
Another busy week of Apple news and rumors has wrapped up, with a lot of focus on Tim Cook's appearance at a Congressional antitrust hearing and a blockbuster earnings report. Subscribe to the MacRumors YouTube channel for more videos. We continued to hear rumors about the upcoming iPhone 12 lineup, including a rare admission from Apple that the lineup will launch "a few weeks later" than...

Emails Reveal Why Steve Jobs and Phil Schiller Blocked In-App Purchase of Kindle Books

Friday July 31, 2020 6:25 am PDT by
Internal Apple emails, made public by the House Judiciary Committee's antitrust inquiry, have revealed information about why Apple blocked in-app purchases of Kindle books on iOS devices, reports The Verge. Two sets of emails between Steve Jobs, Phil Schiller, Eddy Cue, and various other senior Apple executives, disclose the exact thinking behind how Apple approached Kindle on iOS. The...

Battery Likely for Upcoming Apple Watch Series 6 Filed in Certification Listings

Saturday August 1, 2020 5:46 am PDT by
A battery likely for the upcoming Apple Watch Series 6 has been filed at the Korea Testing and Research Institute and discovered by a Twitter user @yabhishekhd. Certification for a 1.17Wh battery with a capacity of 303.8mAh was issued on June 23 by the KTR, a Korean regulatory body that approves and tests new hardware ahead of public sale. The battery seems to be destined for a future...

Apple Marks Return of NHL With New 'Hockey Tape' Ad Shot on iPhone 11 Pro

Saturday August 1, 2020 2:33 am PDT by
Apple today marked the return of NHL hockey with a new "Shot on iPhone" ad on its YouTube channel in Canada. Titled "Hockey Tape," the 30-second video features Vegas Golden Knights players Marc-André Fleury and Mark Stone having some on-ice fun with the iPhone 11 Pro, which they attach to the boards, a hockey stick, and a skate with hockey tape. "See the game like never before with Ultra ...

Apple Launches New Gift Card for 'Everything Apple'

Friday July 31, 2020 3:45 am PDT by
Apple has introduced a new single gift card in the U.S. for all things Apple. First spotted by iCulture, the card can be used at the App Store and other online services, but you can also use it to buy products and accessories in the Apple Store. Previously, there were two separate Apple gift cards available: iTunes cards, which can be used for App Store, iTunes Store, and iCloud storage...

Leaker Jon Prosser Claims iPhone 12 and New iPads Will Launch in October

Wednesday July 29, 2020 4:15 pm PDT by
Leaker Jon Prosser, who has a somewhat mixed track record when it comes to predicting Apple's plans, today said that new iPhone 12 models and new iPads will launch in October. Multiple rumors have suggested that some or all of the iPhone 12 models coming this year will see a later than normal launch. Apple typically unveils and releases new iPhones in the month of September, but problems...