[sudo-users] Unable to sudo following centos5.3 to centos5.5 upgrade

[Todd C. Miller]

This is fixed in sudo-1.7.2p8.  I believe the change in question is:
    http://www.sudo.ws/repos/sudo/rev/64f1b9282984

You have a couple of options:

1) build sudo-1.7.2p8 yourself
2) get sudo-1.7.2p1-7.el5_5.src.rpm and add that change to the
   patches in it, then rpmbuild it.
3) Use the sudo-1.7.4 rpm from http://www.sudo.ws/sudo/download.html

 - todd