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TMA-ROCKY8-3.3.1.17

Ensure net.ipv4.conf.default.log_martians is configured

보통레벨 1자동linux

설명

When enabled, this feature logs packets with un-routable source addresses to the kernel log. net.ipv4.conf.default.log_martians controls if IPv4 packets with un-routable source addresses on a newly added network interface is logged to the kernel log.

점검 방법

감사 방식: 셸 명령

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.default.log_martians 1; then echo compliant; fi
예상 출력
compliant

조치 방법

조치 방식: 가이드 또는 인프라 패치

1. Review all files being used by systemd sysctl and comment out or remove all net.ipv4.conf.default.log_martians lines that are not net.ipv4.conf.default.log_martians=1. Example script: #!/usr/bin/env bash { l_option="net.ipv4.conf.default.log_martians" 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 …

속성

운영 체제
rocky-8
태그
cis-convertedkernellinuxsysctl
참고 자료
CIS Rocky Linux 8 Benchmark v3.0.0 - 3.3.1.17

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