[Samba] Error when joining new DC

[Peter Mittermayer]

In the meantime I also did a lot of testing to find out where exactly the issue starts. This is what I found:
4.13.13 still works. I can joing a DC running this version without problem.
4.13.14 show exactly the same error as I also see on 4.21.

So what exactly was changed between these two versions? According to release notes there have just been a few security fixes. I don't see how any of these can be responsible for the changed behavior:

o CVE-2016-2124:  SMB1 client connections can be downgraded to plaintext
                  authentication.
                  https://www.samba.org/samba/security/CVE-2016-2124.html

o CVE-2020-25717: A user on the domain can become root on domain members.
                  https://www.samba.org/samba/security/CVE-2020-25717.html
                  (PLEASE READ! There are important behaviour changes described)

o CVE-2020-25718: Samba AD DC did not correctly sandbox Kerberos tickets issued
                  by an RODC.
                  https://www.samba.org/samba/security/CVE-2020-25718.html

o CVE-2020-25719: Samba AD DC did not always rely on the SID and PAC in Kerberos
                  tickets.
                  https://www.samba.org/samba/security/CVE-2020-25719.html

o CVE-2020-25721: Kerberos acceptors need easy access to stable AD identifiers
                  (eg objectSid).
                  https://www.samba.org/samba/security/CVE-2020-25721.html

o CVE-2020-25722: Samba AD DC did not do suffienct access and conformance
                  checking of data stored.
                  https://www.samba.org/samba/security/CVE-2020-25722.html

o CVE-2021-3738:  Use after free in Samba AD DC RPC server.
                  https://www.samba.org/samba/security/CVE-2021-3738.html

o CVE-2021-23192: Subsequent DCE/RPC fragment injection vulnerability.
                  https://www.samba.org/samba/security/CVE-2021-23192.html