I think I've solved the problem with 5.12+ firmware.
Now the localhost:9101/change requires some form of authentication.
After some poking around with tcpdump I've managed to find the following solution:
9101 POSTs require to authenticate with
AuthToken field.
The value is then compared with current session token that's stored in...
/tmp/session_token (it changes every reboot at least).
I'm uploading modified
cc_update.py (it has to be replaced in extensions/librariansync)
Code:
201101:165222 system: I LibrarianSync:cc_update:: Sending commands...
201101:165223 system: I LibrarianSync:cc_update:: Success.
201101:165223 system: I LibrarianSync:main:: Done in 0.63s.
I've verified in for PW4 5.13.2 and 5.13.3