Nginx Modsecurity would make LibreNMS unable to edit widget and show errors in dashboard

[fweng322]

When editing dashboard, I could add a widget with its default settings, but when I tried to edit the settings I was not able to save the settings. LibreNMS showed an empty error dialog in the upper-right corner.

However I could edit and save it successfully when I disable the Modsecurity module in nginx (set to modsecurity off in nginx.conf). Just that ModSecurity is a necessary module in that server, so disabling that is not a solution for me.

I couldn’t find any document / discussion about this issue on Internet.

The output of ./validate.php:

$ ./validate.php 
====================================
Component | Version
--------- | -------
LibreNMS  | 22.3.0-3-g9c127bfd4
DB Schema | 2022_02_03_164059_increase_auth_id_length (235)
PHP       | 7.4.28
Python    | 3.9.2
MySQL     | 10.5.12-MariaDB-0+deb11u1
RRDTool   | 1.7.2
SNMP      | 5.9
====================================

[OK]    Composer Version: 2.2.9
[OK]    Dependencies up-to-date.
[OK]    Database connection successful
[OK]    Database schema correct

Any help will be appreciated.

[ottorei]

This module is not officially supported but if you still wish to use it I recommend you to enable additional logging on Nginx and check the logs to see what causes this issue. See the docs on Nginx manual:

Installing the NGINX ModSecurity WAF | NGINX ModSecurity WAF