Ensure TCP SYN Cookies is enabled

SedangLevel 1Otomatisbottlerocket

Deskripsi

When tcp_syncookies is set, the kernel will handle TCP SYN packets normally until the half-open connection queue is full, at which time, the SYN cookie functionality kicks in. SYN cookies work by not using the SYN queue at all. The audit reads the running value from /proc/sys. Run tmaegis on the host through the admin container root shell (sudo sheltie).

Cara pemeriksaan

Metode audit: Perintah shell

shell

bad=0
chk() { f=/proc/sys/$(printf %s "$1" | tr . /); v=$(cat "$f" 2>/dev/null) || { echo "$1: not readable"; bad=1; return; }; [ "$v" = "$2" ] || { echo "$1 = $v (expected $2)"; bad=1; }; }
chk net.ipv4.tcp_syncookies 1
[ "$bad" -eq 0 ] && echo compliant

Output yang diharapkan: compliant

Cara perbaikan

Metode perbaikan: Panduan atau patch infrastruktur

Run the following command to set the active kernel parameter and persist the setting: # apiclient apply <<EOF [settings.kernel.sysctl] "net.ipv4.tcp_syncookies" = "1" EOF Run the following command to flush the routing cache: # sysctl -w net.ipv4.route.flush=1

Properti

Sistem operasi: Apa saja
Tag: bottlerocketnetwork
Referensi: CIS Bottlerocket Benchmark v1.0.0 - 3.2.7 Ensure TCP SYN Cookies is enabled

Periksa host ini

Jalankan ini pada mesin yang diizinkan untuk Anda audit. Pemindaian bersifat hanya baca.

shell

tmaegis scan --target bottlerocket