Scientific Linux Security Update : dhcp on SL6.x i386/x86_64

High Nessus Plugin ID 64949


The remote Scientific Linux host is missing one or more security updates.


A flaw was found in the way the dhcpd daemon handled the expiration time of IPv6 leases. If dhcpd's configuration was changed to reduce the default IPv6 lease time, lease renewal requests for previously assigned leases could cause dhcpd to crash. (CVE-2012-3955)

This update also fixes the following bugs :

- Prior to this update, the DHCP server discovered only the first IP address of a network interface if the network interface had more than one configured IP address. As a consequence, the DHCP server failed to restart if the server was configured to serve only a subnet of the following IP addresses. This update modifies network interface addresses discovery code to find all addresses of a network interface. The DHCP server can also serve subnets of other addresses.

- Prior to this update, the dhclient rewrote the /etc/resolv.conf file with backup data after it was stopped even when the PEERDNS flag was set to 'no' before shut down if the configuration file was changed while the dhclient ran with PEERDNS=yes. This update removes the backing up and restoring functions for this configuration file from the dhclient-script. Now, the dhclient no longer rewrites the /etc/resolv.conf file when stopped.

After installing this update, all DHCP servers will be restarted automatically.


Update the affected packages.

See Also

Plugin Details

Severity: High

ID: 64949

File Name: sl_20130221_dhcp_on_SL6_x.nasl

Version: $Revision: 1.4 $

Type: local

Agent: unix

Published: 2013/03/01

Modified: 2016/01/17

Dependencies: 12634

Risk Information

Risk Factor: High


Base Score: 7.1

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:C

Vulnerability Information

CPE: x-cpe:/o:fermilab:scientific_linux

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/RedHat/release, Host/RedHat/rpm-list

Patch Publication Date: 2013/02/21

Reference Information

CVE: CVE-2012-3955