Connecting to Windows Server 2022 not possible since Cumulative Update 2023-07

[bastolino]

PLEASE, FOLLOW AS CLOSELY AS POSSIBLE THE FOLLOWING SCRIPT TO FILL A BUG REPORT (and remove hints and instructions)

Describe the bug
Connecting to Windows Server 2022 not possible since Cumulative Update 2023-07

Reproduction Steps

• Server configured with BSI Group policy version 1.1 / "high" => https://www.bsi.bund.de/SharedDocs/Downloads/DE/BSI/Cyber-Sicherheit/SiSyPHus/Workpackage12_GPOs_V1_1.html; manually edited to allow incoming RDP sessions with network level authentication (kerberos)
• get kerberos ticket via kinit @<DOMAIN.NAME>
• execute "rdesktop -a 32 -g 1800x900 -u -p - -d .<domain.name> -vv"
  Output:
  Autoselecting keyboard map 'de' from locale
  Password:
  is_wm_active(): WM name: GNOM
  Connecting to server using NLA...
  Core(warning): Certificate received from server is NOT trusted by this system, an exception has been added by the user to trust this specific certificate.
  TLS Session info: (TLS1.2)-(RSA)-(AES-256-GCM)

Connection established using CredSSP.
Core(error): tcp_recv(), gnutls_record_recv() failed with -54: Fehler in der Pull-Funktion.

Expected behavior
Connection to server opens up and user is being logged in

Screenshots
Output of the terminal session as seen above.

Important Information:

• rdesktop Version (*): 1.9.0
• Client OS (*): Ubunutu 22.04
• Server OS: Windows Server 2022
• Server Software: RDP
• Server Software Version: possibly Windows RDP 10 (?)

Checklist

• [y] This bug prevents me from using rdesktop
• [n] This bug is a security issue
• [y] This bug causes a bad experience with rdesktop
• [y] I have supplied all possible sections of the bug report template

Additional Information
Add any relevant contextual information or other details about the problem here, like command line arguments, output, environment variables, gdb output, screenshots, etc.
HINT: the output is often useful, run rdesktop with the -v argument (verbose) to produce a more detailed output.

[bastolino]

Just as a hint: the described procedure has worked seemlessly with more than one Ubuntu device before patching the windows servers and stopped working right after the update+reboot of the windows machine.
Most probably it's some kind of windows bugfix that's preventing rdesktop from working as it should.

[bastolino]

I found out that the real reason was that the corresponding user did not have sufficient permissions any more (due to whatever bug in Windows, though).
Windows mstsc.exe correctly reports the error with missing permissions for remote desktop. Should be done in rdesktop aswell.