Ensure bogus ICMP responses are ignored

中级别 1自动化linux

说明

Setting icmp_ignore_bogus_error_responses to 1 prevents the kernel from logging bogus responses (RFC-1122 non-compliant) from broadcast reframes, keeping file systems from filling up with useless log messages.

检查方式

审计方法: Shell 命令

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.icmp_ignore_bogus_error_responses 1; then echo compliant; fi

预期输出: compliant

修复方式

修复方法: 操作指南或基础设施补丁

Set the following parameter in /etc/sysctl.conf or a /etc/sysctl.d/* file: net.ipv4.icmp_ignore_bogus_error_responses = 1 Run the following commands to set the active kernel parameters: # sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1 # sysctl -w net.ipv4.route.flush=1

属性

操作系统: sles-11
标签: cis-convertedkernellinuxsysctl
参考: CIS SUSE Linux Enterprise 11 Benchmark v2.1.1 - 3.2.6

检查本机

请在您有权审计的机器上运行此命令。扫描为只读操作。

shell

tmaegis scan --target linux