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RHEL 5: RHSA-2023:1140-01 Moderate: DHCP Denial of Service Attack

red hat
Calendar Grey August 2, 2012
Scroller Redhat
Recent updates to the dhcp packages fix a denial of service vulnerability in Red Hat Enterprise Linux 5, improving system security.
Updated dhcp packages that fix one security issue are now available for Red Hat Enterprise Linux 5

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/knowledge/articles/11258

Summary

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.

Topics%20covered

Topics Covered

security advisory moderate Red Hat update DoS DHCP network protocol

References

https://access.redhat.com/security/cve/CVE-2012-3571 https://access.redhat.com/security/updates/classification/#moderate

Package List

Red Hat Enterprise Linux Desktop (v. 5 client):
Source:
i386: dhclient-3.0.5-31.el5_8.1.i386.rpm dhcp-debuginfo-3.0.5-31.el5_8.1.i386.rpm libdhcp4client-3.0.5-31.el5_8.1.i386.rpm
x86_64: dhclient-3.0.5-31.el5_8.1.x86_64.rpm dhcp-debuginfo-3.0.5-31.el5_8.1.i386.rpm dhcp-debuginfo-3.0.5-31.el5_8.1.x86_64.rpm libdhcp4client-3.0.5-31.el5_8.1.i386.rpm libdhcp4client-3.0.5-31.el5_8.1.x86_64.rpm
RHEL Desktop Workstation (v. 5 client):
Source:
i386: dhcp-3.0.5-31.el5_8.1.i386.rpm dhcp-debuginfo-3.0.5-31.el5_8.1.i386.rpm dhcp-devel-3.0.5-31.el5_8.1.i386.rpm libdhcp4client-devel-3.0.5-31.el5_8.1.i386.rpm
x86_64: dhcp-3.0.5-31.el5_8.1.x86_64.rpm dhcp-debuginfo-3.0.5-31.el5_8.1.i386.rpm dhcp-debuginfo-3.0.5-31.el5_8.1.x86_64.rpm dhcp-devel-3.0.5-31.el5_8.1.i386.rpm dhcp-devel-3.0.5-31.el5_8.1.x86_64.rpm libdhcp4client-devel-3.0.5-31.el5_8.1.i386.rpm libdhcp4client-devel-3.0.5-31.el5_8.1.x86_64.rpm
Red Hat Enterprise Linux (v. 5 server):
Source:
i386: dhclient-3.0.5-31.el5_8.1.i386.rpm dhcp-3.0.5-31.el5_8.1.i386.rpm dhcp-debuginfo-3.0.5-31.el5_8.1.i386.rpm dhcp-devel-3.0.5-31.el5_8.1.i386.rpm libdhcp4client-3.0.5-31.el5_8.1.i386.rpm libdhcp4client-devel-3.0.5-31.el5_8.1.i386.rpm
ia64: dhclient-3.0.5-31.el5_8.1.ia64.rpm dhcp-3.0.5-31.el5_8.1.ia64.rpm

Read the Full Advisory


Advisory ID: RHSA-2012:1140-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2012:1140.html
Issue date: 2012-08-03

Topic

Updated dhcp packages that fix one security issue are now available forRed Hat Enterprise Linux 5.The Red Hat Security Response Team has rated this update as having moderatesecurity impact. A Common Vulnerability Scoring System (CVSS) base score,which gives a detailed severity rating, is available from the CVE link inthe References section.

Topics%20covered

Topics Covered

security advisory moderate Red Hat update DoS DHCP network protocol

Relevant Releases Architectures

RHEL Desktop Workstation (v. 5 client) - i386, x86_64

Red Hat Enterprise Linux (v. 5 server) - i386, ia64, ppc, s390x, x86_64

Red Hat Enterprise Linux Desktop (v. 5 client) - i386, x86_64

Bugs Fixed

842420 - CVE-2012-3571 dhcp: DoS due to error in handling malformed client identifiers

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