The function sub_41D354() is used to parse HTTP headers. When handling the 'user-agent', it directly copies the header value to 0x589cec without checking the string length. This could result in out-of-bound writing.
This allows an unauthorized attacker to perform a DoS attack, and possibly remote code execution.
buf = b'GET / HTTP/1.1\\r\\nUser-Agent: ' + b'A'*0x300 + b"\\r\\n\\r\\n"