On Samsung SmartThings Hub STH-ETH-250 devices with firmware version 0.20.17, the video-core process incorrectly extracts fields from a user-controlled JSON payload, leading to a buffer overflow on the stack. An attacker can send an HTTP request to trigger this vulnerability. The memcpy call overflows the destination buffer, which has a size of 512 bytes. An attacker can send an arbitrarily long "url" value in order to overwrite the saved-PC with 0x42424242.
https://www.talosintelligence.com/vulnerability_reports/TALOS-2018-0574