xrdp -- Improper handling of session establishment errors allows bypassing OS-level session restrictions

xrdp team reports:

In versions prior to 0.9.23 improper handling of session establishment
errors allows bypassing OS-level session restrictions. The auth_start_session
function can return non-zero (1) value on, e.g., PAM error which may result
in session restrictions such as max concurrent sessions per user by PAM
(ex ./etc/security/limits.conf) to be bypassed. Users (administrators) don’t
use restrictions by PAM are not affected. This issue has been addressed in
release version 0.9.23. Users are advised to upgrade. There are no known
workarounds for this issue.