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V-256957

CAT II (Medium)

The Automation Controller NGINX web server must limit the character set used for data entry.

Rule ID

SV-256957r1155090_rule

STIG

Red Hat Ansible Automation Controller Web Server Security Technical Implementation Guide

Version

V2R3

CCIs

None

Discussion

It is important that Automation Controller NGINX web server limit the character set used for data entry and disallow Unicode use in hosted applications to avoid application compromise. Definition of the available character set for data entry can trap efforts to bypass security checks. The presence of nonstandard characters may cause the browser to interpret the content using a different character set than the defined one, because the system may interpret the content using a different CHARSET. Nonstandard encodings like UTF-7 can be used to bypass the application's defensive filters. If character sets for data entry are not defined, it leaves open the door for attackers to bypass security checks and make the server vulnerable to malicious attack.

Check Content

As a system administrator (SA) for each Automation Controller NGINX web server, verify the configuration requires a charset is mandatory.

grep 'charset_required' "$(nginx -V 2>&1 | tr ' ' '\n' | sed -ne '/conf-path/{s/.*conf-path=\(.*\)/\1/;p}')" || echo "FAILED"

If "FAILED" is displayed, this is a finding.

Fix Text

As an SA for each Automation Controller NGINX web server, verify the NGINX web server configuration file in use is located at '/etc/nginx/nginx.conf'

NGINXCONF=`nginx -V 2>&1 | tr ' ' '\n' | sed -ne '/conf-path/{s/.*conf-path=\(.*\)/\1/;p}' ` ; 

Add the directive to the NGINX configuration to force a required charset.

sed -i  '/location/i charset_required; ' $NGINXCONF

Reload the NGINX server configurations for all NGINX processes.

$ pkill -HUP nginx