Ensure Browser Framing Is Restricted

LowLevel 2Automatedapache

Description

To prevent Clickjacking or UI Redressing attacks, it's important for the server to include an HTTP header which instructs browsers to restrict the content from being framed. There are two headers that may be used. The Content-Security-Policy header, or the X- Frame-Options header. The Header directive allows server HTTP response headers to be added, replaced or merged. Compliant when a Header always set/append Content-Security-Policy with frame-ancestors 'none' or 'self', or a Header always set/append X-Frame-Options SAMEORIGIN/DENY, is configured. Reads the main configuration (APACHE_CONF overrides; default /etc/apache2/apache2.conf, /etc/httpd/conf/httpd.conf or /usr/local/apache2/conf/httpd.conf) and every Include/IncludeOptional file.

How it is checked

Audit method: Shell command

shell

c=${APACHE_CONF:-}; if [ -z "$c" ]; then for f in /etc/apache2/apache2.conf /etc/httpd/conf/httpd.conf /usr/local/apache2/conf/httpd.conf /etc/apache2/httpd.conf; do [ -f "$f" ] && { c=$f; break; }; done; fi; [ -r "$c" ] || exit 1; R=$(awk 'tolower($1)=="serverroot"{v=$2; gsub(/"/,"",v); print v; exit}' "$c"); [ -n "$R" ] || R=$(dirname "$c"); shopt -s nocasematch; inc(){ local p g l; [ ${#FUNCNAME[@]} -lt 16 ] || return 0; p=$1; case $p in /*) ;; *) p=$R/$p;; esac; [ -d "$p" ] && p="$p/*"; for g in $p; do [ -f "$g" ] || continue; while IFS= read -r l || [ -n "$l" ]; do if [[ $l =~ ^[[:space:]]*include(optional)?[[:space:]]+\"?([^\"[:space:]]+) ]]; then inc "${BASH_REMATCH[2]}"; else printf '%s\n' "$l"; fi; done < "$g"; done; }; cfg=$(inc "$c" | sed -e 's/^[[:space:]]*//' -e '/^#/d' -e '/^$/d'); shopt -u nocasematch; printf '%s\n' "$cfg" | awk '{l=tolower($0)} l~/^header[[:space:]]+always[[:space:]]+(set|append)[[:space:]]+"?content-security-policy/ && l~/frame-ancestors[[:space:]]+\047?(none|self)/{ok=1} l~/^header[[:space:]]+always[[:space:]]+(set|append)[[:space:]]+"?x-frame-options"?[[:space:]]+"?(sameorigin|deny)/{ok=1} END{print ok?"compliant":"noncompliant"}'

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Header always append Content-Security-Policy "frame-ancestors 'self'" Then run apachectl configtest and reload Apache.

Properties

Operating systems: Any
Tags: apacheheaders
Reference: CIS Apache HTTP Server 2.4 Benchmark v2.4.0 - 5.16 Ensure Browser Framing Is Restricted

Check this host

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

shell

tmaegis scan --target apache --level 2