Cannot exploit in the last step about cve-2021-3129 HOT 2 CLOSED

My pleasure.
Your log file contains two copies of phar binary data, it is not difficult to understand why the signature is wrong.
The solution is to add a character at the end of the payload so that only one of the two payloads can always be decoded.
You can see in my exploit.py
payload = f.read().replace('\n', '') + 'a'

from cve-2021-3129.

Thank you so much. Now it's work like a charm. :)

from cve-2021-3129.