Synopsis: Low: sudo security, bug fix and enhancement update
Advisory ID: SLSA-2013:1701-2
Issue Date: 2013-11-21
CVE Numbers: CVE-2013-1775
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,
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.
* 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”.
* 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.
* 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.
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.
* With this update, sudo has been modified to accept the ipa_hostname
value from the /etc/sssd/sssd.conf configuration file when matching
– Scientific Linux Development Team