iOS Bug Causes Specific Network Name to Disable Wi-Fi on iPhones

A wireless network naming bug has been discovered in iOS that effectively disables an iPhone's ability to connect to Wi-Fi.

ios wifi settings
Security researcher Carl Schou found that after joining a Wi-Fi network with the name "%p%s%s%s%s%n" his ‌iPhone‌'s Wi-Fi functionality was left "permanently disabled."

Changing a hotspot's SSID did nothing to correct the problem, with even a reboot failing to make a difference, according to BleepingComputer.

Other users who were able to replicate the issue have suggested the bug could be related to the initial use in the network name of the percentage sign, which leads to an input parsing issue whereby iOS mistakenly interprets the letters following the "%" as a string-format specifier.


In C and C-style languages, string format specifiers have a special meaning and are parsed by the language compiler as a variable name or a command instead of standard text.

Android phones don't seem to be affected by the same network, but iPhones hit by the problem need to have their network settings reset before a Wi-Fi hotspot can be connected again.

To perform the reset, open the Settings app, tap General -> Reset, then tap Reset Network Settings and confirm the request at the prompt.

Top Rated Comments

GubbyMan Avatar
23 months ago
This will always be relevant https://xkcd.com/327/
Score: 64 Votes (Like | Disagree)
acorntoy Avatar
23 months ago
Now Macrumors has led this from ~10 affected idiots to ~10,000. I encourage you to try it though, your device might be special and immune.
Score: 47 Votes (Like | Disagree)
Carlson-online Avatar
23 months ago
Pretty sure of course this big will effect nobody as who would use that as a network name ?!
Score: 22 Votes (Like | Disagree)
PinkyMacGodess Avatar
23 months ago
The real question is why would iOS do anything with the SSID? It's a 'string'. If iOS is choking on it, it shouldn't be looking at it as filet mignon! (Bad analogy warning?) It's like eating the wrapper your hamburger came in. Come on Apple...
Score: 21 Votes (Like | Disagree)
JetLaw Avatar
23 months ago
Changing my SSID right now to %s%s%s%p to test thi [user disconnected]
Score: 21 Votes (Like | Disagree)
bsolar Avatar
23 months ago

Agreed. Who cares about a bug that will effect literally one person out of 1 billion, when there are bigger fish to fry.
It affects basically nobody as long as it's just a joke SSID encountered by chance, but it highlights a vulnerability in the software which malicious actors can further investigate and potentially have the chance to further exploit.

That's why Apple should promptly fix the root issue before worse exploits have a chance to happen.
Score: 21 Votes (Like | Disagree)

Popular Stories

dynamic island

iPhone 15 Dynamic Island to Include New Integrated Proximity Sensor

Friday March 24, 2023 12:27 am PDT by
This year, all iPhone 15 models will include Apple's Dynamic Island that unifies the pill and hole cutouts at the top of the display, but there will also be a material change to the feature that wasn't included in the iPhone 14 Pro models. According to a new tweet by Apple industry analyst Ming-Chi Kuo, the proximity sensor on the iPhone 15 series will be integrated inside the Dynamic Island ...
apple park at night 1

Apple 'Tracking Employee Attendance' in Crackdown on Remote Working

Thursday March 23, 2023 3:41 am PDT by
Apple is tracking the attendance of its employees at offices using badge records in order to ensure they are coming in at least three times a week, according to Platformer's Zoë Schiffer. Since April 2022, Apple employees have been operating on a hybrid home/office work policy as part of a gradual return strategy following the pandemic, with staff required to work from the office at least...
iphone 14 pro max deep purple feature purple

iPhone 15 Pro Rumor Recap: 10 New Features and Changes to Expect

Thursday March 23, 2023 6:42 am PDT by
While the iPhone 15 series is still around six months away from launching, there have already been plenty of rumors about the devices. Many new features and changes have been rumored for the iPhone 15 Pro and iPhone 15 Pro Max in particular. Below, we have recapped 10 changes rumored for iPhone 15 Pro models that are not expected to be available on the standard iPhone 15 and iPhone 15 Plus:A1...
maxresdefault

Nothing Launches $149 Ear (2) Wireless Earbuds to Compete With AirPods Pro 2

Wednesday March 22, 2023 9:48 am PDT by
Nothing today announced the launch of its second-generation wireless earbuds, the Nothing Ear (2), which offer many of the same features as Apple's AirPods Pro 2 at a lower price point. We went hands-on with the Ear (2) earbuds to see whether they're a viable alternative to the AirPods Pro 2 for those who want to save some cash. The Ear (2) earbuds are the successor to the Nothing Ear (1),...
TMobile Sprint

Apple Stops Allowing Sprint iPhone Activations, Removes Sprint References From Online Store

Thursday March 23, 2023 12:06 pm PDT by
Apple is no longer allowing customers who purchase an iPhone, cellular iPad, or Apple Watch to activate a device with now-defunct mobile carrier Sprint. Apple has also removed remaining references to Sprint from its online store. When checking out with a new purchase, Sprint is no longer an option for connectivity, a change that Apple appears to have implemented today. Prior to now, Sprint...
iOS 16

iOS 16.4 for iPhone Nearing Launch With These 5 New Features

Monday March 20, 2023 11:50 am PDT by
Apple says iOS 16.4 is coming in the spring, which began this week. In his Sunday newsletter, Bloomberg's Mark Gurman said the update should be released "in the next three weeks or so," meaning a public release is likely in late March or early April. iOS 16.4 remains in beta testing and introduces a handful of new features and changes for the iPhone. Below, we have recapped five new features ...
Hero0009

Best Apple Deals of the Week: Samsung's Smart Monitor M8 Gets Massive $250 Discount, Along With Year's Best AirPods Prices

Friday March 24, 2023 10:23 am PDT by
We saw a lot of great deals on Apple products and related accessories this week, including Samsung's iMac-like Smart Monitor M8 for $250 off, a 30 percent off spring sale at Anker, and the year's best prices on numerous AirPods models. All of these deals are still available to purchase right now, so we're recapping them and more below. Note: MacRumors is an affiliate partner with some of these ...
top stories 25mar2023

Top Stories: iPhone 15 Pro Design Leak, iOS 16.4 Coming Soon, and More

Saturday March 25, 2023 6:00 am PDT by
We're still almost six months away from the official unveiling of the iPhone 15 lineup, but it seems like every day we're learning more about what to expect from the next-generation models. Notably, this week gave us our clearest look yet at what appear to be some changes for the volume and mute control hardware. iOS 16.4 and associated releases are also right around the corner with some new ...