An issue was discovered on certain Nuki Home Solutions devices. The code used to parse the JSON objects received from the WebSocket service provided by the device leads to a stack buffer overflow. An attacker would be able to exploit this to gain arbitrary code execution on a KeyTurner device. This affects Nuki Smart Lock 3.0 before 3.3.5 and 2.0 before 2.12.4, as well as Nuki Bridge v1 before 1.22.0 and v2 before 2.13.2.
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.