sudo (SL6)

Synopsis: Moderate: sudo security, bug fix, and enhancement update
Advisory ID: SLSA-2015:1409-1
Issue Date: 2015-07-22
CVE Numbers: CVE-2014-9680

It was discovered that sudo did not perform any checks of the TZ
environment variable value. If sudo was configured to preserve the TZ
environment variable, a local user with privileges to execute commands via
sudo could possibly use this flaw to achieve system state changes not
permitted by the configured commands. (CVE-2014-9680)

Note: The default sudoers configuration in Scientific Linux 6 removes the TZ
variable from the environment in which commands run by sudo are executed.

This update also fixes the following bugs:

* Previously, the sudo utility child processes could sometimes become
unresponsive because they ignored the SIGPIPE signal. With this update,
SIGPIPE handler is properly restored in the function that reads passwords
from the user, and the child processes no longer ignore SIGPIPE. As a
result, sudo child processes do not hang in this situation.

* Prior to this update, the order in which sudo rules were processed did
not honor the user-defined sudoOrder attribute. Consequently, sudo rules
were processed in an undefined order even when the user defined the order
in sudoOrder. The implementation of SSSD support in sudo has been modified
to sort the rules according to the sudoOrder value, and sudo rules are now
sorted in the order defined by the user in sudoOrder.

* Previously, sudo became unresponsive after the user issued a command
when a sudoers source was mentioned multiple times in the
/etc/nsswitch.conf file. The problem occurred when nsswitch.conf
contained, for example, the “sudoers: files sss sss” entry. The sudoers
source processing code has been fixed to correctly handle multiple
instances of the same sudoers source. As a result, sudo no longer hangs
when a sudoers source is mentioned multiple times in /etc/nsswitch.conf.

In addition, this update adds the following enhancement:

* The sudo utility now supports I/O logs compressed using the zlib
library. With this update, sudo can generate zlib compressed I/O logs and
also process zlib compressed I/O logs generated by other versions of sudo
with zlib support.


– Scientific Linux Development Team