Stack-Based Buffer Overflow in Newtec's update signaling causes RCE

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in Newtec NTC2218, NTC2250, NTC2299 on Linux, PowerPC, ARM (Updating signaling process in the swdownload binary modules) allows Local Execution of Code, Remote Code Inclusion. This issue affects NTC2218, NTC2250, NTC2299: from 1.0.1.1 through 2.2.6.19. The issue is both present on the PowerPC versions of the modem and the ARM versions. A stack buffer buffer overflow in the swdownload binary allows attackers to execute arbitrary code. The parse_INFO function uses an unrestricted `sscanf` to read a string of an incoming network packet into a statically sized buffer.