Scientific Linux Security Update : sudo on SL5.x i386/x86_64

This script is Copyright (C) 2012 Tenable Network Security, Inc.


Synopsis :

The remote Scientific Linux host is missing a security update.

Description :

An insecure temporary file use flaw was found in the sudo package's
post-uninstall script. A local attacker could possibly use this flaw
to overwrite an arbitrary file via a symbolic link attack, or modify
the contents of the '/etc/nsswitch.conf' file during the upgrade or
removal of the sudo package. (CVE-2012-3440)

This update also fixes the following bugs :

- Previously, sudo escaped non-alphanumeric characters in
commands using 'sudo -s' or 'sudo -' at the wrong place
and interfered with the authorization process. Some
valid commands were not permitted. Now, non-alphanumeric
characters escape immediately before the command is
executed and no longer interfere with the authorization
process. (BZ#844418)

- Prior to this update, the sudo utility could, under
certain circumstances, fail to receive the SIGCHLD
signal when it was executed from a process that blocked
the SIGCHLD signal. As a consequence, sudo could become
suspended and fail to exit. This update modifies the
signal process mask so that sudo can exit and sends the
correct output. (BZ#844419)

- The sudo update RHSA-2012:0309 introduced a regression
that caused the Security-Enhanced Linux (SELinux)
context of the '/etc/nsswitch.conf' file to change
during the installation or upgrade of the sudo package.
This could cause various services confined by SELinux to
no longer be permitted to access the file. In reported
cases, this issue prevented PostgreSQL and Postfix from
starting. (BZ#842759)

- Updating the sudo package resulted in the 'sudoers' line
in '/etc/nsswitch.conf' being removed. This update
corrects the bug in the sudo package's post-uninstall
script that caused this issue. (BZ#844420)

- Prior to this update, a race condition bug existed in
sudo. When a program was executed with sudo, the program
could possibly exit successfully before sudo started
waiting for it. In this situation, the program would be
left in a zombie state and sudo would wait for it
endlessly, expecting it to still be running. (BZ#844978)

See also :

http://www.nessus.org/u?ad0abd47
https://bugzilla.redhat.com/show_bug.cgi?id=842759
https://bugzilla.redhat.com/show_bug.cgi?id=844418
https://bugzilla.redhat.com/show_bug.cgi?id=844419
https://bugzilla.redhat.com/show_bug.cgi?id=844420
https://bugzilla.redhat.com/show_bug.cgi?id=844978

Solution :

Update the affected sudo package.

Risk factor :

Medium / CVSS Base Score : 5.6
(CVSS2#AV:L/AC:H/Au:N/C:N/I:C/A:C)

Family: Scientific Linux Local Security Checks

Nessus Plugin ID: 61456 ()

Bugtraq ID:

CVE ID: CVE-2012-3440