Resolved Apache2/ mod security2 error

[Onkeltom01]

Server operating system version

CentOS 7.9

Plesk version and microupdate number

Plesk Obsidian 18.0.70 Update 2

Hi all,
today morning my Webserver stops working with following error:

Jul  4 08:27:32 server1 systemd: Starting The Apache HTTP Server...
Jul  4 08:27:32 server1 httpd: httpd: Syntax error on line 353 of /etc/httpd/conf/httpd.conf: Syntax error on line 1 of /etc/httpd/conf.d/security2.conf: Cannot load modules/mod_security2.so into server: /etc/httpd/modules/mod_security2.so: undefined symbol: pcre2_set_depth_limit
Jul  4 08:27:32 server1 systemd: httpd.service: main process exited, code=exited, status=1/FAILURE
Jul  4 08:27:32 server1 systemd: Failed to start The Apache HTTP Server.
Jul  4 08:27:32 server1 systemd: Unit httpd.service entered failed state.
Jul  4 08:27:32 server1 systemd: httpd.service failed.
Jul  4 08:27:32 server1 apache_control_adapter[17736]: apache_action(start): invoke_httpd_action failed, trying second time
Jul  4 08:27:32 server1 systemd: Starting The Apache HTTP Server...
Jul  4 08:27:32 server1 httpd: httpd: Syntax error on line 353 of /etc/httpd/conf/httpd.conf: Syntax error on line 1 of /etc/httpd/conf.d/security2.conf: Cannot load modules/mod_security2.so into server: /etc/httpd/modules/mod_security2.so: undefined symbol: pcre2_set_depth_limit
Jul  4 08:27:32 server1 systemd: httpd.service: main process exited, code=exited, status=1/FAILURE
Jul  4 08:27:32 server1 systemd: Failed to start The Apache HTTP Server.
Jul  4 08:27:32 server1 systemd: Unit httpd.service entered failed state.
Jul  4 08:27:32 server1 systemd: httpd.service failed.

any idea to fix this?

Best regards,
Tom

 

[Sebahat.hadzhi]

Hello, Tom. It looks like the issue might be related to corruption in ModSecurity. Could you please re-installing the ModSecurity component?

 

[Onkeltom01]

Okay, thank you for your reply Sebahat.hadzhi, I can try this later this evening because of downtime.
In the meanwhile I stopped the Web Application Firewall (ModSecurity) to ensure the reachiabilty of the websites.

But what happened today morning?
automated updated?

The "00_mod_security.conf" and "security2.conf" at /etc/httpd/conf.d Directory where changed this morning at 08:17:40
also the most configured Modules from Tools&Settings => Apache Webserver Konfiguration lost the activation mark.
The Watchdog mentioned the apache down at 08:20 via eMail.

I didn't manual update the server at this time!

 

[Onkeltom01]

Re-installing ModSecurity did the trick.
Now https are running back again with ModSecurity.

thanks sebahat.hadzhi for your support!

Best Regard,
Tom

 

[Sebahat.hadzhi]

I am glad to hear the issue is sorted, Tom. If you have automatic updates enabled, likely something was not properly compiled during the update process. However, I cannot confirm what exactly went wrong. For further investigation, I can suggest opening a ticket with Plesk support so our engineers can review the case in detail directly on the server.