A recent update to the widely used Apache web server, released via cPanel's EasyApache 4 system, has caused multiple websites to fail due to configuration conflicts. Server administrators reported that the upgrade to Apache 2.4.64 triggered "421 Misdirected Request" errors, particularly on websites running with EA-Nginx or reverse proxy setups. The error prevented affected websites from displaying pages correctly to visitors. Further complications arose for servers using the ModSecurity web application firewall. A shift to the newer PCRE2 regular expression engine caused Apache to crash or fail to restart, due to syntax incompatibilities in some security rule sets. One widely reported issue stemmed from the Comodo ruleset, specifically the 30_Apps_OtherApps.conf file, which contained a malformed expression that broke Apache's startup. cPanel has acknowledged the issue and is working on a resolution under internal reference EA-13040. In the meantime, the company advised server administrators to review their error logs and disable or manually correct the affected rules as a temporary workaround. ModSecurity is widely deployed for web security, and Comodo provides one of the most commonly used rule sets. However, recent changes to the way Apache handles regex parsing have led to unforeseen compatibility issues. Experts recommend that administrators audit their configurations and apply caution when rolling out major updates to ensure service continuity and system stability. Attribution: Amwal Al Ghad English Subediting: M. S. Salama
