TMA-ROCKY8-3.3.1.12
Ensure net.ipv4.conf.all.rp_filter is configured
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
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
Periksa host ini
Jalankan ini pada mesin yang diizinkan untuk Anda audit. Pemindaian bersifat hanya baca.
tmaegis scan --target linux