Title

The operating system must prevent internal users from sending out packets which attempt to manipulate or spoof invalid IP addresses. (Cat II impact)

Discussion

Manipulation of IP addresses can allow untrusted systems to appear as trusted hosts, bypassing firewall and other security mechanism and resulting in system penetration.

Check Content

Determine the zone that you are currently securing. # zonename If the command output is "global", then only the "phys" and "SR-IOV" interfaces assigned to the global zone require inspection. If using a non-Global zone, then all "phys" and "SR-IOV" interfaces assigned to the zone require inspection. Identify if this system has physical interfaces. # dladm show-link -Z | grep -v vnic LINK ZONE CLASS MTU STATE OVER net0 global phys 1500 unknown -- e1000g0 global phys 1500 up -- e1000g1 global phys 1500 up -- zoneD/net2 zoneD iptun 65515 up -- If "phys" appears in the third column, then the interface is physical. For each physical interface, determine if the network interface is Ethernet or InfiniBand: # dladm show-phys [interface name] LINK MEDIA STATE SPEED DUPLEX DEVICE [name] Ethernet unknown 0 half dnet0 The second column indicates either "Ethernet" or "Infiniband". For each physical interface, determine if the host is using ip-forwarding: # ipadm show-ifprop [interface name] | grep forwarding [name] forwarding ipv4 rw off -- off on,off [name] forwarding ipv6 rw off -- off on,off If "on" appears in the fifth column, then the interface is using ip-forwarding. For each interface, determine if the host is using SR-IOV’s Virtual Function (VF) driver: # dladm show-phys [interface name] | grep vf If the sixth column includes 'vf' in its name, it is using SR-IOV (ex: ixgbevf0). For each physical and SR-IOV interface, determine if network link protection capabilities are enabled. # dladm show-linkprop -p protection LINK PROPERTY PERM VALUE DEFAULT POSSIBLE net0 protection rw mac-nospoof, -- mac-nospoof, restricted, restricted, ip-nospoof, ip-nospoof, dhcp-nospoof dhcp-nospoof If the interface uses Infiniband and if restricted, ip-nospoof, and dhcp-nospoof do not appear in the "VALUE" column, this is a finding. If the interface uses ip-forwarding and if mac-nospoof, restricted, and dhcp-nospoof do not appear in the "VALUE" column, this is a finding. If the interface uses SR-IOV and if mac-nospoof, restricted, and dhcp-nospoof do not appear in the "VALUE" column, this is a finding. If the interface uses Ethernet without IP forwarding and if mac-nospoof, restricted, ip-nospoof, and dhcp-nospoof do not appear in the "VALUE" column, this is a finding.

Fix Text

Determine the name of the zone that you are currently securing. # zonename If the command output is "global", then only the "phys" and "SR-IOV" interfaces assigned to the global zone require configuration. If using a non-Global zone, then all "phys" and "SR-IOV" interfaces assigned to the zone require configuration. The Network Link Security profile is required. Determine which network interfaces are available and what protection modes are enabled and required. Enable link protection based on each configured network interface type. For InfiniBand: # pfexec dladm set-linkprop -p protection=restricted,ip-nospoof,dhcp-nospoof [interface name] For IP forwarding: # pfexec dladm set-linkprop -p protection=mac-nospoof,restricted,dhcp-nospoof [interface name] For SR-IOV: # pfexec dladm set-linkprop -p protection=mac-nospoof,restricted,dhcp-nospoof [interface name] For Ethernet without IP forwarding: # pfexec dladm set-linkprop -p protection=mac-nospoof,restricted,ip-nospoof,dhcp-nospoof [interface name]

Additional Identifiers

Rule ID: SV-216400r603267_rule

Vulnerability ID: V-216400

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.