Guide to the Secure Configuration of Ubuntu 18.04
Rules, Groups, and Values defined within the XCCDF Benchmark
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net.ipv4.icmp_echo_ignore_broadcasts
Ignore all ICMP ECHO and TIMESTAMP requests sent to it via broadcast/multicastValue -
net.ipv4.icmp_ignore_bogus_error_responses
Enable to prevent unnecessary loggingValue -
net.ipv4.tcp_invalid_ratelimit
Configure the maximal rate for sending duplicate acknowledgments in response to incoming invalid TCP packets.Value -
net.ipv4.tcp_rfc1337
Enable to enable TCP behavior conformant with RFC 1337Value -
net.ipv4.tcp_syncookies
Enable to turn on TCP SYN Cookie ProtectionValue -
Disable Accepting Packets Routed Between Local Interfaces
To set the runtime status of the <code>net.ipv4.conf.all.accept_local</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w net...Rule Medium Severity -
Configure ARP filtering for All IPv4 Interfaces
To set the runtime status of the <code>net.ipv4.conf.all.arp_filter</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w net.i...Rule Medium Severity -
Configure Response Mode of ARP Requests for All IPv4 Interfaces
To set the runtime status of the <code>net.ipv4.conf.all.arp_ignore</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w net.i...Rule Medium Severity -
Prevent Routing External Traffic to Local Loopback on All IPv4 Interfaces
To set the runtime status of the <code>net.ipv4.conf.all.route_localnet</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w n...Rule Medium Severity -
Configure Sending and Accepting Shared Media Redirects for All IPv4 Interfaces
To set the runtime status of the <code>net.ipv4.conf.all.shared_media</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w net...Rule Medium Severity -
Configure Sending and Accepting Shared Media Redirects by Default
To set the runtime status of the <code>net.ipv4.conf.default.shared_media</code> kernel parameter, run the following command: <pre>$ sudo sysctl -w...Rule Medium Severity -
Network Parameters for Hosts Only
If the system is not going to be used as a router, then setting certain kernel parameters ensure that the host will not perform routing of network ...Group -
nftables
<code>If firewalld or iptables are being used in your environment, please follow the guidance in their respective section and pass-over the guidanc...Group -
Nftables Base Chain Hooks
The possible hooks which can be used to configure the base chain are: <code>ingress</code> (only in netdev family since Linux kernel 4.2, and inet ...Value -
Nftables Chain Names
The rules in nftables are attached to chains. Unlike in iptables, there are no predefined chains like INPUT, OUTPUT, etc. Instead, to filter pack...Value -
Nftables Base Chain Policies
This is the default verdict that will be applied to packets reaching the end of the chain (i.e, no more rules to be evaluated against). Currently ...Value -
Nftables Base Chain Priorities
Each nftables base chain is assigned a priority that defines its ordering among other base chains, flowtables, and Netfilter internal operations a...Value -
Nftables Base Chain Types
Base chains are those that are registered into the Netfilter hooks, i.e. these chains see packets flowing through the Linux TCP/IP stack. The poss...Value -
Nftables Families
Netfilter enables filtering at multiple networking levels. With iptables there is a separate tool for each level: iptables, ip6tables, arptables, ...Value -
Nftables Master configuration file
The file which contains top level configuration for nftables service, and with which, the service is started.Value
Node 2
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