/etc/pam.d/tigervnc is in tigervnc-common 1.7.0+dfsg-8ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | #%PAM-1.0
@include common-auth
@include common-account
@include common-session-noninteractive
|