Linux distributions
TMA-UBUNTU2604-1.5.2
Ensure fs.protected_symlinks is configured
Deskripsi
fs.protected_symlinks Controls how the kernel handles symbolic links. More information about the kernel parameter configuration files, their location, and load preference is available in the section overview.
Cara pemeriksaan
Metode audit: Perintah 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 $f in configuration"; return 1;; esac; }; if chk fs.protected_symlinks 1; then echo compliant; fi- Output yang diharapkan
compliant
Cara perbaikan
Metode perbaikan: Panduan atau patch infrastruktur
1. Review all files being used by systemd-sysctl and comment out or remove all fs.protected_symlinks lines that are not fs.protected_symlinks=1. Example script: #!/usr/bin/env bash { l_option="fs.protected_symlinks" l_value="1" l_grep="${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 "$l_file" ] && ! grep -Psiq -- '(^|\h+)…
Properti
- Sistem operasi
- ubuntu-26.04
- Tag
- cis-convertedkernellinuxsysctl
- Referensi
- CIS Ubuntu Linux 26.04 LTS Benchmark v1.0.0 - 1.5.2
Periksa host ini
Jalankan ini pada mesin yang diizinkan untuk Anda audit. Pemindaian bersifat hanya baca.
tmaegis scan --target linux --level 2