Getting Root On Cheap WiFi Repeaters, The Long Way Around

What can you do with a cheap Linux machine with limited flash and only a single free GPIO line? Probably not much, but sometimes, just getting root to prove you can is the main goal of a project. If that happens to lead somewhere useful, well, that’s just icing on the cake.

Like many interesting stories, this one starts on AliExpress, where [Easton] spied some low-cost WiFi repeaters, the ones that plug directly into the wall and extend your wireless network another few meters or so. Unable to resist the siren song, a few of these dongles showed up in the mailbox, ripe for the hacking. Spoiler alert: although the attempt on the first device had some success by getting a console session through the UART port and resetting the root password, [Easton] ended up bricking the repeater while trying to install an OpenWRT image.

The second attempt, this time on a different but similar device, proved more fruitful. The rudimentary web UI provided no easy path in, although it did a pretty good job enumerating the hardware [Easton] was working with. With the UART route only likely to provide temptation to brick this one too, [Easton] turned to a security advisory about a vulnerability that allows remote code execution through a specially crafted SSID. That means getting root on these dongles is as simple as a curl command — no hardware hacks needed!

As for what to do with a bunch of little plug-in Linux boxes with WiFi, we’ll leave that up to your imagination. We like [Easton]’s idea of running something like Pi-Hole on them; maybe Home Assistant would be possible, but these are pretty resource-constrained machines. Still, the lessons learned here are valuable, and at this price point, let the games begin.

A client uses an Augmented Alternative Communication board that speaks.

Tactile Communication Board Speaks The Truth

Sometimes, simple things can make a world of difference. Take for example a non-verbal person who can’t necessarily control a touch screen in order to tell someone else what they need or want or think.

The switches of the AAC board, plus the smaller version. This is where Augmentative and Alternative Communication (AAC) devices come in. Recently tasked with building such a device, [Thornhill!] came up with a great design that houses 160 different phrases in a fairly small package and runs on CircuitPython.

Basically, the client presses the appropriate snap-dome button button and the corresponding phrase is spoken through the speaker. The 10×16 grid of buttons is covered with a membrane that both feels nice and gives a bit of protection from spills.

The buttons can achieve high actuation forces and have a crisp tactile response, which means they’re probably gonna go a long way to keep the user from getting frustrated.

This handy AAC board is built on the Adafruit RP2040 Prop-Maker Feather and two keypad matrices. If this weren’t useful enough as it is, [Thornhill!] also built an even smaller version with 16 buttons for the client to wear around their neck.

Did you know? AAC boards aren’t just for humans.