Ensure tcp_tcpsecure is configured

MediumLevel 1Automatedaix

Description

The tcp_tcpsecure parameter value determines if the system is protected from three specific TCP vulnerabilities: The values are ORed together. If all three values are to be set the value to set is: 1|2|4 (or 7). Fake SYN - This is used to terminate an established connection. A tcp_tcpsecure bit-value of 1 protects the system from this vulnerability. Audit: `no -o tcp_tcpsecure` must report 7.

How it is checked

Audit method: Shell command

shell

command -v no >/dev/null 2>&1 || exit 1; out=$(no -o tcp_tcpsecure 2>/dev/null) || exit 1; printf '%s\n' "$out" | sed 's/[[:blank:]]*=[[:blank:]]*/=/'

Expected output: tcp_tcpsecure=7

How it is fixed

Fix method: Guidance or infrastructure patch

no -p -o tcp_tcpsecure=7 (sets the running value and makes it persistent in /etc/tunables/nextboot)

Properties

Operating systems: Any
Tags: aixhardening
Reference: CIS IBM AIX 7 Benchmark v1.2.0 - 4.5.17 Ensure tcp_tcpsecure is configured

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target aix