Synopsis:    Low: sudo security and bug fix update
Issue Date:  2012-02-21
CVE Numbers: CVE-2011-0010


The sudo (superuser do) utility allows system administrators to give
certain users the ability to run commands as root.

A flaw was found in the sudo password checking logic. In configurations
where the sudoers settings allowed a user to run a command using sudo
with only the group ID changed, sudo failed to prompt for the user's
password before running the specified command with the elevated group
privileges. (CVE-2011-0010)

In addition, this update fixes the following bugs:

* A NULL pointer dereference bug caused the sudo utility to terminate
unexpectedly with a segmentation fault. This happened if the utility was
run with the -g option and configured not to demand the password from the
user who ran the sudo utility. With this update, the code has been modified
and the problem no longer occurs. 

* The sudo utility failed to load sudoers from an LDAP (Lightweight
Directory Access Protocol) server after the sudo tool was upgraded. This
happened because the upgraded nsswitch.conf file did not contain the
instruction to search for sudoers on the LDAP server. This update adds the
lost instruction to /etc/nsswitch.conf and the system searches for sources
of sudoers on the local file system and then on LDAP, if applicable.

* The sudo tool interpreted a Runas alias specifying a group incorrectly as
a user alias and the alias seemed to be ignored. With this update, the code
for interpreting such aliases has been modified and the Runas group aliases
are honored as expected. 

* Prior to this update, sudo did not parse comment characters (#) in the
ldap.conf file correctly and could fail to work. With this update, parsing
of the LDAP configuration file has been modified and the comment characters
are parsed correctly. 

* The sudo utility formats its output to fit the width of the terminal
window. However, this behavior is undesirable if the output is redirected
through a pipeline. With this update, the output formatting is not applied
in the scenario described. 

* Previously, the sudo utility performed Security-Enhanced Linux (SELinux)
related initialization after switching to an unprivileged user. This
prevented the correct setup of the SELinux environment before executing the
specified command and could potentially cause an access denial. The bug has
been fixed by backporting the SELinux related code and the execution model
from a newer version of sudo. 
* On execv(3) function failure, the sudo tool executed an auditing call
before reporting the failure. The call reset the error state and,
consequently, the tool incorrectly reported that the command succeeded.
With this update, the code has been modified and the problem no longer
occurs. 

All users of sudo are advised to upgrade to this updated package, which
resolves these issues.

SL5:
  i386
     sudo-1.7.2p1-13.el5.i386.rpm
     sudo-debuginfo-1.7.2p1-13.el5.i386.rpm
  x86_64
     sudo-1.7.2p1-13.el5.x86_64.rpm
     sudo-debuginfo-1.7.2p1-13.el5.x86_64.rpm

- Scientific Linux Development Team