In July of 2010 we wrote an article titled “Forget this Network, Pretty Please” on how the iPhone and other iOS devices offer no way to easily remove known wireless networks. For those that aren’t familiar with this concept, known wireless networks are ones you connect to once and the iPhone remembers them. Depending on how you configure your iDevice, it will automatically reconnect to these known networks for instant access to the Internet without having to manually reconnect.
For example, you manually connect to “attwifi” at Starbucks and then head home. The next day you return and your phone automatically connects to “attwifi” with no extra effort. It is primarily a convenience feature but one that of course brings up many security issues. Not only is your phone constantly broadcasting this network ID out along with location information that others could passively track, but it opens MITM attacks as well. For this reason Brian Krebbs years ago recommended removing known networks by “click[ing] ‘Settings,’ ‘Wi-Fi Networks,’ select the wireless network’s name, and then ‘Forget this Network.'”
(Note: As part of a campaign to bring forward some of our older posts that we feel still benefit the community, we’ve added this article to our Best Of category that will periodically get tweeted out. Please mention it to me on Twitter or contact us if there are any other posts you feel we should include in this category. This post was previously categorized under Infosec Blogs/Podcasts. [email protected]grecs)
This recommendation is fine but unfortunately there was no way to remove individual wifi networks from the list of known networks. Your only option was to head back to that Starbucks, let your phone automatically reconnect, and press the “Forget this Network” button under that wireless network’s properties. And as we discussed before another option could involve setting up your own access point and configuring the SSID to attwifi, connecting to it, and then doing the “Forget this Network” thing.
We wrote that original piece way back in 2010 and absolutely nothing has changed since … except for a possible solution recently recommended by David “@darthnull” Schuetz. Simple navigate to Settings -> General -> Reset and iOS includes a “Reset Network Settings” option. Pressing this button will fix your problem of removing those unforgettable wifi networks. Of course it will also remove the ones you want to keep too.
Know of any other ways to fix this problem? Let us know in the comments below. See ya!