At the recent BSidesRI conference in Rhode Island, USA, James Edge presented an overview of the TP-Link WR703N wireless router, and how it is modifiable akin to the WRT54G. (The manufacturer’s website does not contain documentation for the 703N. The linked doc is for the 702N, which has many of the same features and functions as the 703N. However, as corrected in the comments, note that the WR702N is not the same as the 703N, in that it has less Flash and thus cannot run the same hacked firmware.)
The WR703N is a compact economy device which includes the Atheros AR9331, a 400 MHz ARM processor and 4 GB Flash. Out of the box it supports AP Mode, Router Mode, Client Mode, Repeater Mode and Bridge Mode. James discusses expandability, including doubling memory and Flash, and adding interfaces for a Teensy, serial and GPIO connections. The modded firmware he used was from the OpenWRT group.
The talk seems long on the hardware end (some of which is of the “here’s the memory mod I paid someone to do” variety) with too few details on firmware hacks and exploits. It does, however, introduce us to a new and economical WiFi hacking platform, inspiring further research.
(Note: the talk’s substance begins at 5:30.)