Red Hat Security Advisory: dhcp security update Security Advisory secalert@redhat.com Red Hat Security Response Team RHSA-2012:1140 Final 1 1 2012-08-03T00:13:00Z Current version 2012-08-03T00:13:00Z 2012-08-03T00:13:00Z Red Hat rhsa-to-cvrf 1.0.1484 2012-08-03T00:34:01Z Updated dhcp packages that fix one security issue are now available for Red Hat Enterprise Linux 5. The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section. The Dynamic Host Configuration Protocol (DHCP) is a protocol that allows individual devices on an IP network to get their own network configuration information, including an IP address, a subnet mask, and a broadcast address. A denial of service flaw was found in the way the dhcpd daemon handled zero-length client identifiers. A remote attacker could use this flaw to send a specially-crafted request to dhcpd, possibly causing it to enter an infinite loop and consume an excessive amount of CPU time. (CVE-2012-3571) Upstream acknowledges Markus Hietava of the Codenomicon CROSS project as the original reporter of this issue. Users of DHCP should upgrade to these updated packages, which contain a backported patch to correct this issue. After installing this update, all DHCP servers will be restarted automatically. Please see https://www.redhat.com/footer/terms-of-use.html Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate https://rhn.redhat.com/errata/RHSA-2012-1140.html https://rhn.redhat.com/errata/RHSA-2012-1140.html https://access.redhat.com/security/updates/classification/#moderate https://access.redhat.com/security/updates/classification/#moderate http://www.isc.org/software/dhcp/advisories/cve-2012-3571 http://www.isc.org/software/dhcp/advisories/cve-2012-3571 Red Hat Enterprise Linux Desktop (v. 5 client) Red Hat Enterprise Linux (v. 5 server) RHEL Desktop Workstation (v. 5 client) dhcp-3.0.5-31.el5_8.1.src.rpm dhcp-3.0.5-31.el5_8.1 as a component of Red Hat Enterprise Linux Desktop (v. 5 client) dhcp-3.0.5-31.el5_8.1 as a component of Red Hat Enterprise Linux (v. 5 server) dhcp-3.0.5-31.el5_8.1 as a component of RHEL Desktop Workstation (v. 5 client) A denial of service flaw was found in the way the dhcpd daemon handled zero-length client identifiers. A remote attacker could use this flaw to send a specially-crafted request to dhcpd, possibly causing it to enter an infinite loop and consume an excessive amount of CPU time. 2012-07-23T00:00:00Z 2012-07-24T00:00:00Z CVE-2012-3571 5Client-5.8.Z:dhcp-3.0.5-31.el5_8.1 5Client-Workstation-5.8.Z:dhcp-3.0.5-31.el5_8.1 5Server-5.8.Z:dhcp-3.0.5-31.el5_8.1 Moderate 3.3 AV:A/AC:L/Au:N/C:N/I:N/A:P 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/knowledge/articles/11258 https://rhn.redhat.com/errata/RHSA-2012-1140.html https://www.redhat.com/security/data/cve/CVE-2012-3571.html CVE-2012-3571 https://bugzilla.redhat.com/show_bug.cgi?id=842420 bz#842420: CVE-2012-3571 dhcp: DoS due to error in handling malformed client identifiers Upstream acknowledges Markus Hietava of Codenomicon CROSS project as the original reporter of this issue.