Comment 22 for bug 1644428

The same issue is observed on Xenial:

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 16.04.2 LTS
Release: 16.04
Codename: xenial

ii libpam-gnome-keyring:amd64 3.18.3-0ubuntu2 amd64
ii libpam-modules:amd64 1.1.8-3.2ubuntu2 amd64
ii libpam-modules-bin 1.1.8-3.2ubuntu2 amd64
ii libpam-pwquality:amd64 1.3.0-0ubuntu1 amd64
ii libpam-runtime 1.1.8-3.2ubuntu2 all
ii libpam-sss:amd64 1.13.4-1ubuntu1.2 amd64
ii libpam-systemd:amd64 229-4ubuntu16 amd64
ii libpam0g:amd64 1.1.8-3.2ubuntu2 amd64
ii python-samba 2:4.3.11+dfsg-0ubuntu0.16.04.3 amd64
ii samba 2:4.3.11+dfsg-0ubuntu0.16.04.3 amd64
ii samba-common 2:4.3.11+dfsg-0ubuntu0.16.04.3 all
ii samba-common-bin 2:4.3.11+dfsg-0ubuntu0.16.04.3 amd64
ii samba-dsdb-modules 2:4.3.11+dfsg-0ubuntu0.16.04.3 amd64
ii samba-libs:amd64 2:4.3.11+dfsg-0ubuntu0.16.04.3 amd64
ii samba-vfs-modules 2:4.3.11+dfsg-0ubuntu0.16.04.3 amd64

From /var/log/auth.log:
10:48:56 gcc-ubuntu-tst1 sudo: gcc : problem with defaults entries ; TTY=pts/18 ; PWD=/etc/sssd ;
10:48:56 gcc-ubuntu-tst1 sudo: PAM unable to dlopen( /lib/security/ cannot open shared object file: No such file or directory
10:48:56 gcc-ubuntu-tst1 sudo: PAM adding faulty module:
10:48:56 gcc-ubuntu-tst1 sudo: gcc : TTY=pts/18 ; PWD=/etc/sssd ; USER=root ; COMMAND=/bin/more sssd.conf
10:48:56 gcc-ubuntu-tst1 sudo: pam_unix(sudo:session): session opened for user root by gcc(uid=0)
10:48:56 gcc-ubuntu-tst1 sudo: pam_unix(sudo:session): session closed for user root