Data saved to a Tesco Hudl is vulnerable to recovery thanks to a bug in its core processor
Hiding data by using a factory reset option does little to delete potentially sensitive information, suggest researchers.
Three separate investigations of Android's data deleting systems found it was possible to recover information.
In some cases, a reset just removed the list of where data was stored and deleted nothing else.
In particular, Tesco's Hudl tablet was found to have a flaw that let attackers get at data saved to onboard memory.
All the investigations used second-hand devices sold via auction sites such as eBay.
There is a known bug in the Rockchip processor at its heart.
All modern gadgets can be flipped into a "flash mode" so the onboard firmware can be updated and data written to the device.