3DS System Flaws
Exploits are used to execute unofficial code (homebrew) on the Nintendo 3DS. This page is a list of known 3DS-mode exploits.
List of 3DS Exploits
There are currently no known 3DS-mode exploits.
Tips and info
Information on the 3DS's internals is scarce, notably the following:
Flash encryption type/key(s) Gamecard encryption key(s) Memory mappings Pica200 GPU registers and general programming info (commands, setup, etc.) Many other things
What this means is if any exploits are found, it would be very difficult to do anything useful with them.
There are similarities between the 3DS and it's predecessors that could be used to communicate with an outside device (PC, microcontroller, etc.), one of them being the WiFi chip, which is very similar between the 3DS and DSi. Theoretically, if you could launch some code on the 3DS via an exploit, you could initialize the WiFi chip in the 3DS, connect to an access point, then connect to some network connected device, and send and receive data from the 3DS to the network connected device. This would allow you to do memory dumps over WiFi, upload code to the 3DS, etc.
Another method would be to dump the contents of the 3DS's RAM through a hardware modification. This can be done by soldering connections to the 3DS's RAM and connecting it to an FPGA or similar device. The 3DS would then be powered on and it would modify and use RAM as it normally would, and then the hacker can disengage the 3DS from it's RAM (through a switch, etc.) or access the RAM through the FPGA while the 3DS is still using it. A good example of this type of modification is bushing's work with the DSi (link).