(RHSA-2015:1409) Moderate: sudo security, bug fix, and enhancement update

ID RHSA-2015:1409
Type redhat
Reporter RedHat
Modified 2018-06-06T20:24:14


The sudo packages contain the sudo utility which allows system administrators to provide certain users with the permission to execute privileged commands, which are used for system management purposes, without having to log in as root.

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 Red Hat Enterprise Linux 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. (BZ#1094548)

  • 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. (BZ#1138581)

  • 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. (BZ#1147498)

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. (BZ#1106433)

All sudo users are advised to upgrade to these updated packages, which contain backported patches to correct these issues and add this enhancement.