Rule ID
SV-265428r994634_rule
Version
V1R2
CCIs
A malicious platform can use a compromised host in an enclave to launch cyberattacks on third parties. This is a common practice in "botnets", which are a collection of compromised computers using malware to attack other computers or networks. Distributed denial-of-service (DDoS) attacks frequently leverage IP source address spoofing to send packets to multiple hosts that in turn will send return traffic to the hosts with the IP addresses that were forged. This can generate significant amounts of traffic. Therefore, protection measures to counteract IP source address spoofing must be taken. When uRPF is enabled in strict mode, the packet must be received on the interface that the device would use to forward the return packet; thereby mitigating IP source address spoofing.
From the NSX Manager web interface, go to Networking >> Connectivity >> Tier-0 Gateways. For every Tier-0 Gateway, expand Tier-0 Gateway >> Interfaces and GRE Tunnels, and then click on the number of interfaces present to open the interfaces dialog. Expand each interface to view the URPF Mode configuration. If URPF Mode is not set to "Strict" on any interface, this is a finding.
Enable strict URPF mode on interfaces by doing the following: From the NSX Manager web interface, go to Networking >> Connectivity >> Tier-0 Gateways and expand the target Tier-0 gateway. Expand "Interfaces and GRE Tunnels", click on the number of interfaces present to open the interfaces dialog, and then select "Edit" on the target interface. From the drop-down, set the URPF mode to "Strict" and then click "Save".