1.39.1. RHSA-2011:0428: Important security update
Updated dhcp packages that fix one security issue are now available for Red Hat Enterprise Linux 4, 5, and 6.
The Red Hat Security Response Team has rated this update as having important 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.
It was discovered that the DHCP client daemon, dhclient, did not sufficiently sanitize certain options provided in DHCP server replies, such as the client hostname. A malicious DHCP server could send such an option with a specially-crafted value to a DHCP client. If this option's value was saved on the client system, and then later insecurely evaluated by a process that assumes the option is trusted, it could lead to arbitrary code execution with the privileges of that process. (CVE-2011-0997)
Red Hat would like to thank Sebastian Krahmer of the SuSE Security Team for reporting this issue.
All dhclient users should upgrade to these updated packages, which contain a backported patch to correct this issue.
1.39.2. RHSA-2010:0923: Moderate security update
Updated dhcp packages that fix one security issue are now available for Red Hat Enterprise Linux 6.
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. DHCPv6 is the DHCP protocol version for IPv6 networks.
A NULL pointer dereference flaw was discovered in the way the dhcpd daemon parsed DHCPv6 packets. A remote attacker could use this flaw to crash dhcpd via a specially-crafted DHCPv6 packet, if dhcpd was running as a DHCPv6 server. (CVE-2010-3611)
Users running dhcpd as a DHCPv6 server 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.
1.39.3. RHSA-2011:0256: Moderate security update
Updated dhcp packages that fix one security issue are now available for Red Hat Enterprise Linux 6.
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. DHCPv6 is the DHCP protocol version for IPv6 networks.
A flaw was found in the way the dhcpd daemon processed certain DHCPv6 messages for addresses that had previously been declined and marked as abandoned internally. If a remote attacker sent such messages to dhcpd, it could cause dhcpd to crash due to an assertion failure if it was running as a DHCPv6 server. (CVE-2011-0413)
Red Hat would like to thank Internet Systems Consortium for reporting this issue.
Users running dhcpd as a DHCPv6 server 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.
1.39.4. RHBA-2011:0697: bug fix and enhancement update
Updated dhcp packages that fix several bugs and add various enhancements are now available for Red Hat Enterprise Linux 6.
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. DHCPv6 is the DHCP protocol version for IPv6 networks.
This update fixes the following bugs:
Previously, it was impossible to configure the dhcrelay service to run the dhcrelay daemon with additional arguments. With this update, a DHCRELAYARGS variable is available for the /etc/sysconfig/dhcrelay configuration file, which allows additional arguments to be passed to the dhcrelay daemon properly. (
BZ#625846)
Previously, the dhclient utility did not log its PID (process identifier) in syslog entries, making troubleshooting in systems with multiple running dhclients difficult. Now, the dhclient utility logs its PID properly. (
BZ#627257)
Previously, the dhclient utility sometimes parsed date strings in lease files incorrectly, resulting in syntax error messages in its output. This bug has been fixed and the dates in the lease files are now parsed with no error messages given. (
BZ#631071)
When the dhclient utility was updating a "search" entry in the /etc/resolv.conf file, it sometimes did not add a missing domain part. This was inconsistent with NetworkManager behavior. Now, while updating the "search" entry, the dhclient utility always adds the domain part of the host name given to the client if it is missing. (
BZ#637763)
Previously, the dhcpd service with IPv6 support sometimes created a lease file that it was unable to parse. Consequently, once the service was restarted, it went into a loop and could not start. This bug has been fixed and now the service is able to properly parse all lease files it generates. (
BZ#672551)
DHCP servers at some ISPs send to clients the "interface-mtu" option with the value of 576. Such a low MTU (Maximum Transmission Unit) can cause throughput problems with UDP traffic, among other things. With this update, the dhclient utility now sets the interface MTU only if the value obtained from the server is higher than 576. (
BZ#681721)
Previously, the dhclient package was missing its LICENSE file. With this update, the file has been added. (
BZ#613683)
This update adds the following enhancements:
The dhcp package now provides an implementation of Classless Static Route Options for DHCPv4 (RFC 3442). It can supply network route configuration to a large number of hosts without individual configuration of each one. (
BZ#558641)
The dhcp package now provides support for IPoIB (IP over InfiniBand) interfaces. (
BZ#660681)
Users of dhcp are advised to upgrade to these updated packages, which fix these bugs and add these enhancements.
