6.9 - RHSA-2013:1701

Problem Description:

An updated sudo package that fixes two security issues, several bugs, and adds two enhancements is now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having low security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 6) - i386, x86_64 Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - x86_64 Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, x86_64 Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64

3. Description:

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 way sudo handled time stamp files. An attacker able to run code as a local user and with the ability to control the system clock could possibly gain additional privileges by running commands that the victim user was allowed to run via sudo, without knowing the victim's password. (CVE-2013-1775)

It was found that sudo did not properly validate the controlling terminal device when the tty_tickets option was enabled in the /etc/sudoers file. An attacker able to run code as a local user could possibly gain additional privileges by running commands that the victim user was allowed to run via sudo, without knowing the victim's password. (CVE-2013-2776, CVE-2013-2777)

This update also fixes the following bugs:

* Previously, sudo did not support netgroup filtering for sources from the System Security Services Daemon (SSSD). Consequently, SSSD rules were applied to all users even when they did not belong to the specified netgroup. With this update, netgroup filtering for SSSD sources has been implemented. As a result, rules with a netgroup specification are applied only to users that are part of the netgroup. (BZ#880150)

* When the sudo utility set up the environment in which it ran a command, it reset the value of the RLIMIT_NPROC resource limit to the parent's value of this limit if both the soft (current) and hard (maximum) values of RLIMIT_NPROC were not limited. An upstream patch has been provided to address this bug and RLIMIT_NPROC can now be set to "unlimited". (BZ#947276)

* Due to the refactoring of the sudo code by upstream, the SUDO_USER variable that stores the name of the user running the sudo command was not logged to the /var/log/secure file as before. Consequently, user name "root" was always recorded instead of the real user name. With this update, the previous behavior of sudo has been restored. As a result, the expected user name is now written to /var/log/secure. (BZ#973228)

* Due to an error in a loop condition in sudo's rule listing code, a buffer overflow could have occurred in certain cases. This condition has been fixed and the buffer overflow no longer occurs. (BZ#994626)

In addition, this update adds the following enhancements:

* With this update, sudo has been modified to send debug messages about netgroup matching to the debug log. These messages should provide better understanding of how sudo matches netgroup database records with values from the running system and what the values are exactly. (BZ#848111)

* With this update, sudo has been modified to accept the ipa_hostname value from the /etc/sssd/sssd.conf configuration file when matching netgroups. (BZ#853542)

All sudo users are advised to upgrade to this updated package, which contains backported patches to correct these issues and add these enhancements.

4. Solution:

Before applying this update, make sure all previously released errata relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at https://access.redhat.com/site/articles/11258

5. Bugs fixed (https://bugzilla.redhat.com/):

856901 - Defauts:! syntax in sudoers doesn't seem to work as expected 880150 - sssd +netgroup sudoUser is always matched 886648 - Access granted with invalid sudoRunAsUser/sudoRunAsGroup 916363 - CVE-2013-1775 sudo: authentication bypass via reset system clock 949751 - CVE-2013-2776 sudo: bypass of tty_tickets constraints 949753 - CVE-2013-2777 sudo: bypass of tty_tickets constraints 994563 - Warning in visudo: cycle in Host_Alias even without cycle 994626 - sudo -u sudo -l show error: *** glibc detected *** sudo: realloc(): invalid next size: 0x00007f4ae2d10ec0 ***