PHTN-67-000104 - The Photon operating system must not forward IPv4 or IPv6 source-routed packets - net.ipv6.conf.eth0.accept_source_route

Information

Source routing is an Internet Protocol (IP) mechanism that allows an IP packet to carry information, a list of addresses, which tells a router the path the packet must take. There is also an option to record the hops as the route is traversed.

The list of hops taken, the 'route record', provides the destination with a return path to the source. This allows the source (the sending host) to specify the route, loosely or strictly, ignoring the routing tables of some or all of the routers. It can allow a user to redirect network traffic for malicious purposes and should therefore be disabled.

Solution

Open /etc/sysctl.conf with a text editor.

Add or update the following lines:

net.ipv4.conf.all.accept_source_route = 0
net.ipv4.conf.default.accept_source_route = 0
net.ipv4.conf.eth0.accept_source_route = 0
net.ipv6.conf.all.accept_source_route = 0
net.ipv6.conf.default.accept_source_route = 0
net.ipv6.conf.eth0.accept_source_route = 0

Run the following command to load the new setting:

# /sbin/sysctl --load

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_VMW_vSphere_6-7_Y23M07_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b., CAT|II, CCI|CCI-000366, Rule-ID|SV-239175r816656_rule, STIG-ID|PHTN-67-000104, Vuln-ID|V-239175

Plugin: Unix

Control ID: 3688aa2056bdddc6912113927d1204460555a2f5ac2b84c036f36b8f5a4cbfe6