RHSA-2009:1154 - Security Advisory

Topic

Updated dhcp packages that fix two security issues are now available for
Red Hat Enterprise Linux 3.

This update has been rated as having critical security impact by the Red
Hat Security Response Team.

Description

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.

The Mandriva Linux Engineering Team discovered a stack-based buffer
overflow flaw in the ISC DHCP client. If the DHCP client were to receive a
malicious DHCP response, it could crash or execute arbitrary code with the
permissions of the client (root). (CVE-2009-0692)

An insecure temporary file use flaw was discovered in the DHCP daemon's
init script ("/etc/init.d/dhcpd"). A local attacker could use this flaw to
overwrite an arbitrary file with the output of the "dhcpd -t" command via
a symbolic link attack, if a system administrator executed the DHCP init
script with the "configtest", "restart", or "reload" option.
(CVE-2009-1893)

Users of DHCP should upgrade to these updated packages, which contain
backported patches to correct these issues.

Solution

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

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 3 x86_64
• Red Hat Enterprise Linux Server 3 ia64
• Red Hat Enterprise Linux Server 3 i386
• Red Hat Enterprise Linux Workstation 3 x86_64
• Red Hat Enterprise Linux Workstation 3 ia64
• Red Hat Enterprise Linux Workstation 3 i386
• Red Hat Enterprise Linux Desktop 3 x86_64
• Red Hat Enterprise Linux Desktop 3 i386
• Red Hat Enterprise Linux for IBM z Systems 3 s390x
• Red Hat Enterprise Linux for IBM z Systems 3 s390
• Red Hat Enterprise Linux for Power, big endian 3 ppc

Fixes

• BZ - 507717 - CVE-2009-0692 dhclient: stack overflow leads to arbitrary code execution as root
• BZ - 510024 - CVE-2009-1893 dhcp: insecure temporary file use in the dhcpd init script

CVEs

• CVE-2009-0692
• CVE-2009-1893

References

• http://www.redhat.com/security/updates/classification/#critical