After an update Apache won't start with the error: undefined symbol: __xmlParserVersion

Symptoms

Apache fails to start after an update from the Hardened Imunify/CloudLinux repository. The following is logged:

CONFIG_TEXT: httpd: Syntax error on line 282 of /etc/apache2/conf/httpd.conf.work.818368bd.cfgcheck: Syntax error on line 54 of /etc/apache2/conf.d/php.conf: Cannot load /opt/cpanel/ea-php72/root/usr/lib64/apache2/modules/libphp7.so into server: /opt/cpanel/ea-php72/root/usr/lib64/apache2/modules/libphp7.so: undefined symbol: __xmlParserVersion

Cause

Package updates provided by the Imunify360 Hardened PHP are introducing configuration conflicts for libphp modules.

The updates erroneously changed libphp7.so to link against libxml2.so.2 (the system soname) instead of the ea-libxml2 provided libxml2.so.16.

CloudLinux has opened a case to review this further. That case ID is EA4D-816. 

Resolution

CloudLinux has released an update to the testing repository. 

1. Log in as the root user to SSH, or use the WHM Terminal.

2. Run the following command:

   # yum update  ea-apache24-mod_security2 --enablerepo=cl-ea4-testing