Warning- on installing gdm-guest-session cannot be authenticated!

[Jānis Kangarooo]

sudo apt-get install gdm-guest-session
[sudo] password for kangarooo:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
  gdm-guest-session
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 7,570B of archives.
After this operation, 86.0kB of additional disk space will be used.
WARNING: The following packages cannot be authenticated!
  gdm-guest-session
Install these packages without verification [y/N]? y
Get:1 http://security.ubuntu.com/ubuntu/ lucid-security/main gdm-guest-session 0.15ubuntu0.1 [7,570B]
Fetched 7,570B in 0s (45.5kB/s)
Selecting previously unselected package gdm-guest-session.
(Reading database ... 147534 files and directories currently installed.)
Unpacking gdm-guest-session (from .../gdm-guest-session_0.15ubuntu0.1_all.deb) ...
Setting up gdm-guest-session (0.15ubuntu0.1) ...

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: gdm-guest-session 0.15ubuntu0.1
ProcVersionSignature: Ubuntu 2.6.32-39.86-generic 2.6.32.56+drm33.22
Uname: Linux 2.6.32-39-generic i686
Architecture: i386
Date: Tue Mar 13 17:54:23 2012
InstallationMedia: Ubuntu-Netbook 10.04 "Lucid Lynx" - Release i386 (20100429.4)
PackageArchitecture: all
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gdm-guest-session

[dino99 (9d9)]

That version is no more supported; and no expecting backport as it only concern 'security' problem.