Ensure secure ICMP redirects are not accepted

SrednjaNivo 1Automatskalinux

Opis

Secure ICMP redirects are the same as ICMP redirects, except they come from gateways listed on the default gateway list. It is assumed that these gateways are known to your system, and that they are likely to be secure.

Kako se proverava

Metod provere: Komanda ljuske

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.secure_redirects 0 && chk net.ipv4.conf.default.secure_redirects 0; then echo compliant; fi

Očekivani izlaz: compliant

Kako se ispravlja

Metod ispravke: Smernica ili zakrpa infrastrukture

Set the following parameters in /etc/sysctl.conf or a /etc/sysctl.d/* file: net.ipv4.conf.all.secure_redirects = 0 net.ipv4.conf.default.secure_redirects = 0 Run the following commands to set the active kernel parameters: # sysctl -w net.ipv4.conf.all.secure_redirects=0 # sysctl -w net.ipv4.conf.default.secure_redirects=0 # sysctl -w net.ipv4.route.flush=1

Svojstva

Operativni sistemi: alinux-2
Oznake: cis-convertedkernellinuxsysctl
Referenca: CIS Aliyun Linux 2 Benchmark v1.0.0 ARCHIVE - 3.2.3

Proverite ovaj računar

Pokrenite ovo na računaru za koji imate dozvolu za proveru. Skeniranje radi u režimu samo za čitanje.

shell

tmaegis scan --target linux