version 1.9.5p2-2ubuntu1 broke system

just upgraded sudo from 1.9.4p2-2ubuntu3 to 1.9.5p2-2ubuntu1 and sudo does not work any more.

here is the result:

$ sudo ls
sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set

Here is a long ls for sudo binary:
-rwsr-xr-x 1 2001 2501 187K Feb 10 15:12 /usr/bin/sudo

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: sudo 1.9.5p2-2ubuntu1
ProcVersionSignature: Ubuntu 5.10.0-14.15-generic 5.10.11
Uname: Linux 5.10.0-14-generic x86_64
ApportVersion: 2.20.11-0ubuntu58
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Tue Feb 16 13:31:00 2021
InstallationDate: Installed on 2019-11-01 (472 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
RebootRequiredPkgs: gnome-shell
SourcePackage: sudo
UpgradeStatus: No upgrade log present (probably fresh install)
VisudoCheck:
 /etc/sudoers: parsed OK
 /etc/sudoers.d/README: parsed OK
modified.conffile..etc.sudoers: [inaccessible: [Errno 13] Permission denied: '/etc/sudoers']
modified.conffile..etc.sudoers.d.README: [inaccessible: [Errno 13] Permission denied: '/etc/sudoers.d/README']