Linux distributions
TMA-ROCKY9-3.3.1.6
Ensure net.ipv4.icmp_ignore_bogus_error_responses is configured
설명
net.ipv4.icmp_ignore_bogus_error_responses controls if the kernel logs bogus responses (RFC-1122 non-compliant) from broadcast reframes. More information about the kernel parameter configuration files, their location, and load preference is available in the "Configure Network Kernel Parameters" section overview.
점검 방법
감사 방식: 셸 명령
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 $f in configuration"; return 1;; esac; }; if chk net.ipv4.icmp_ignore_bogus_error_responses 1; then echo compliant; fi- 예상 출력
compliant
조치 방법
조치 방식: 가이드 또는 인프라 패치
1. Review all files being used by systemd sysctl and comment out or remove all net.ipv4.icmp_ignore_bogus_error_responses lines that are not net.ipv4.icmp_ignore_bogus_error_responses=1. Example script: #!/usr/bin/env bash { l_option="net.ipv4.icmp_ignore_bogus_error_responses" l_value="1" l_grep="${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…
속성
- 운영 체제
- rocky-9
- 태그
- cis-convertedkernellinuxsysctl
- 참고 자료
- CIS Rocky Linux 9 Benchmark v3.0.0 - 3.3.1.6
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