There is yet another network name out there that has the potential to break an iPhone's Wi-Fi. This isn't the first time this weird issue has come up considering it was only a couple of weeks ago that the same bug was discovered. However, the newer example of the issue appears to be potentially even worse. Here's what you need to know.
Previously, a strange bug was discovered that disabled the iPhone's Wi-Fi capabilities if the user joined a network named '%p%s%s%s%s%n'. While it seems like an extremely random string of characters, it caused a pretty big issue. After joining the network, the device's Wi-Fi functions would all be disabled, including networking features like AirDrop. The only way to remedy the issue was to reset all network settings. Unfortunately, this time there isn't such an easy fix.
Carl Schou, the finder of the original issue, did some more digging and found that a different network name can have even worse effects on an iPhone. Essentially, any network with the name '%secretclub%power' can permanently disable network capabilities. Apparently, even if the iPhone comes within range of the network it will be affected, unlike previously where the user would need to actually join that network in order for the network name to result in a problem. Instead of an easy network reset, a full hard reset is required to repair the iPhone's network functionality. Schou attempted to reset network settings and hard reboot multiple times to no avail, leaving a factory reset the last resort.
Network Name Takes Advantage Of A Coding Weakness
It's thought that the issue is caused due to '%secretclub%power' and '%p%s%s%s%s%n' totally disrupting the internal code format related to iOS Wi-Fi functions. There are some pretty good theories circulating around. For instance, because '%n' is present in the network name, actions are being triggered by this string that normally wouldn't be. According to 9to5 Mac "The Wi-Fi subsystem probably passes the Wi-Fi network name (SSID) unsanitized to some internal library that is performing string formatting, which in turn causes an arbitrary memory write and buffer overflow." Although this one seems to do a lot more damage to an iPhone, it seems unlikely that this will be the last bugged-out network name to surface. It looks as though there are multiple combinations of coding commands that can flow right into iOS unchecked, upping the likelihood this isn't the last of the issue.
While this bug isn't new, it goes without saying that if you see a suspicious network name, don't join the network. It's recommended that the user also makes frequent backups to iCloud in order to avoid losing all of their data in the event that they do come into contact with this malicious network string. The issue may be fixed in a future iOS update from Apple but, as it stands, the only fix is a hard reset.
Sources: Carl Schou/Twitter, 9to5 Mac