CVE-2021-45039: Buffer Copy without Checking Size of Input

Multiple models of the Uniview IP Camera (e.g., IPC_G6103 B6103.16.10.B25.201218, IPC_G61, IPC21, IPC23, IPC32, IPC36, IPC62, and IPC_HCMN) offer an undocumented UDP service on port 7788 that allows a remote unauthenticated attacker to overflow an internal buffer and achieve code execution. By using this buffer overflow, a remote attacker can start the telnetd service. This service has a hardcoded default username and password (root/123456). Although it has a restrictive shell, this can be easily bypassed via the built-in ECHO shell command.