Linux distributions
TMA-ROCKY9-3.3.1.7
Ensure net.ipv4.icmp_echo_ignore_broadcasts is configured
Beschreibung
net.ipv4.icmp_echo_ignore_broadcasts controls if all ICMP echo and timestamp requests to broadcast and multicast addresses are ignored. More information about the kernel parameter configuration files, their location, and load preference is available in the "Configure Network Kernel Parameters" section overview.
So wird geprüft
Prüfmethode: Shell-Befehl
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 $f in configuration"; return 1;; esac; }; if chk net.ipv4.icmp_echo_ignore_broadcasts 1; then echo compliant; fi- Erwartete Ausgabe
compliant
So wird behoben
Behebungsmethode: Anleitung oder Infrastruktur-Patch
1. Review all files being used by systemd sysctl and comment out or remove all net.ipv4.icmp_echo_ignore_broadcasts lines that are not net.ipv4.icmp_echo_ignore_broadcasts=1. Example script: #!/usr/bin/env bash { l_option="net.ipv4.icmp_echo_ignore_broadcasts" l_value="1" l_grep="${l_option//./(\\.|\\/)}" a_files=() l_systemdsysctl="$(readlink -e /lib/systemd/systemd-sysctl \ || readlink -e /usr/lib/systemd/systemd-sysctl)" a_files+=("/etc/sysctl.conf") while IFS= read -r l_fname; do l_file="$(readlink -e "${l_fname//# /}")" [ -n "$l_file" ] && ! grep -Psiq -- '(^|\h+)'"$l_file"'\b' \ <<< "${a_files[*]}" && a_files+=("$l_file") done < <("$l_systemdsysctl" --cat-config | tac | \ grep -Psio --…
Eigenschaften
- Betriebssysteme
- rocky-9
- Tags
- cis-convertedkernellinuxsysctl
- Referenz
- CIS Rocky Linux 9 Benchmark v3.0.0 - 3.3.1.7
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