Red Hat 7: RHSA-2015-2315-01 Moderate: NetworkManager DoS Attack

NetworkManager is a system network service that manages network devices and connections.
It was discovered that NetworkManager would set device MTUs based on MTU values received in IPv6 RAs (Router Advertisements), without sanity checking the MTU value first. A remote attacker could exploit this flaw to create a denial of service attack, by sending a specially crafted IPv6 RA packet to disturb IPv6 communication. (CVE-2015-0272)
A flaw was found in the way NetworkManager handled router advertisements. An unprivileged user on a local network could use IPv6 Neighbor Discovery ICMP to broadcast a non-route with a low hop limit, causing machines to lower the hop limit on existing IPv6 routes. If this limit is small enough, IPv6 packets would be dropped before reaching the final destination. (CVE-2015-2924)
The network-manager-applet and NetworkManager-libreswan packages have been upgraded to upstream versions 1.0.6, and provide a number of bug fixes and enhancements over the previous versions. (BZ#1177582, BZ#1243057)
Bugs:
* It was not previously possible to set the Wi-Fi band to the "a" or "bg" values to lock to a specific frequency band. NetworkManager has been fixed, and it now sets the wpa_supplicant's "freq_list" option correctly, which enables proper Wi-Fi band locking. (BZ#1254461)
* NetworkManager immediately failed activation of devices that did not have a carrier early in the boot process. The legacy network.service then reported activation failure. Now, NetworkManager has a grace period during which it waits for the carrier to appear. Devices that have a carrier down for a short time on system startup no longer cause the legacy network.service to fail. (BZ#1079353)
* NetworkManager brought down a team device if the teamd service managing it exited unexpectedly, and the team device was deactivated. Now, NetworkManager respawns the teamd instances that disappear and is able to recover from a teamd failure avoiding disruption of the team device operation. (BZ#1145988)
* NetworkManager did not send the FQDN DHCP option even if host name was set to FQDN. Consequently, Dynamic DNS (DDNS) setups failed to update the DNS records for clients running NetworkManager. Now, NetworkManager sends the FQDN option with DHCP requests, and the DHCP server is able to create DNS records for such clients. (BZ#1212597)
* The command-line client was not validating the vlan.flags property correctly, and a spurious warning message was displayed when the nmcli tool worked with VLAN connections. The validation routine has been fixed, and the warning message no longer appears. (BZ#1244048)
* NetworkManager did not propagate a media access control (MAC) address change from a bonding interface to a VLAN interface on top of it. Consequently, a VLAN interface on top of a bond used an incorrect MAC address. Now, NetworkManager synchronizes the addresses correctly. (BZ#1264322)
Enhancements:
* IPv6 Privacy extensions are now enabled by default. NetworkManager checks the per-network configuration files, NetworkManager.conf, and then falls back to "/proc/sys/net/ipv6/conf/default/use_tempaddr" to determine and set IPv6 privacy settings at device activation. (BZ#1187525)
* The NetworkManager command-line tool, nmcli, now allows setting the wake-on-lan property to 0 ("none", "disable", "disabled"). (BZ#1260584)
* NetworkManager now provides information about metered connections. (BZ#1200452)
* NetworkManager daemon and the connection editor now support setting the Maximum Transmission Unit (MTU) of a bond. It is now possible to change MTU of a bond interface in a GUI. (BZ#1177582, BZ#1177860)
* NetworkManager daemon and the connection editor now support setting the MTU of a team, allowing to change MTU of a teaming interface. (BZ#1255927)
NetworkManager users are advised to upgrade to these updated packages, which correct these issues and add these enhancements.