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TMA-ROCKY8-3.3.1.12

Ensure net.ipv4.conf.all.rp_filter is configured

SedangLevel 1Otomatislinux

Deskripsi

net.ipv4.conf.all.rp_filter controls reverse path filtering for IPv4 traffic on all network interfaces. Reverse path filtering is a security mechanism in Linux that helps prevent IP spoofing and other network attacks. When enabled, it checks if the source IP address of an incoming packet is reachable through the same network interface it was received on. If the packet's source address is not reachable through the interface it arrived on, the packet is dropped. Note: If this system is a router, and uses asymmetrical routing, this recommendation is not applicable.

Cara pemeriksaan

Metode audit: Perintah shell

shell
chk() { p=$1; allowed=" $2 "; case $p in net.ipv6.*) [ -d /proc/sys/net/ipv6 ] || return 0;; esac; v=$(sysctl -n "$p" 2>/dev/null) || { echo "$p: not available"; return 1; }; case "$allowed" in *" $v "*) ;; *) echo "$p is $v (running)"; return 1;; esac; sd=$(readlink -e /lib/systemd/systemd-sysctl || readlink -e /usr/lib/systemd/systemd-sysctl); f=$("$sd" --cat-config 2>/dev/null | grep -Po "^\h*${p//./\.}\h*=\h*\K\H+" | tail -n1); [ -n "$f" ] || { echo "$p is not set in any sysctl configuration file"; return 1; }; case "$allowed" in *" $f "*) ;; *) echo "$p is $f in configuration"; return 1;; esac; }; if chk net.ipv4.conf.all.rp_filter 1; then echo compliant; fi
Output yang diharapkan
compliant

Cara perbaikan

Metode perbaikan: Panduan atau patch infrastruktur

1. Review all files being used by systemd sysctl and comment out or remove all net.ipv4.conf.all.rp_filter lines that are not net.ipv4.conf.all.rp_filter=1. Example script: #!/usr/bin/env bash { l_option="net.ipv4.conf.all.rp_filter" l_value="1" l_grep="${l_option//./(\\.|\\/)}" a_files=() l_systemdsysctl="$(readlink -e /lib/systemd/systemd-sysctl \ || readlink -e /usr/lib/systemd/systemd-sysctl)" l_ufw_file="$([ -f /etc/default/ufw ] && \ awk -F= '/^\s*IPT_SYSCTL=/ {print $2}' /etc/default/ufw)" [ -f "$(readlink -e "$l_ufw_file")" ] && \ a_files+=("$l_ufw_file"); a_files+=("/etc/sysctl.conf") while IFS= read -r l_fname; do l_file="$(readlink -e "${l_fname//# /}")" [ -n "$l_file" ] && ! grep…

Properti

Sistem operasi
rocky-8
Tag
cis-convertedkernellinuxsysctl
Referensi
CIS Rocky Linux 8 Benchmark v3.0.0 - 3.3.1.12

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shell
tmaegis scan --target linux