Plesk users have recently faced accessibility issues with their hosted websites after an Apache update, encountering a “421 Misdirected Request” error. This issue stems from security patches in the latest Apache version that prevent nginx from processing requests without a server name, which is standard when connecting through a proxy-HTTPS server. To resolve this problem, users need to add specific directives (proxy_ssl_server_name and proxy_ssl_name) to their nginx configuration, allowing nginx to pass the server name via TLS Server Name Indication (SNI) to Apache. Detailed steps can be found on the official Plesk support page.
Security updates in software such as Apache often come with unforeseen consequences for users relying on specific configurations or older systems. In this case, while the update was aimed at enhancing security and stability, it inadvertently caused issues for Plesk hosted sites that use nginx as a proxy. This highlights the importance of staying informed about changes in underlying technologies and having proactive solutions ready to mitigate disruptions.
Third-party information around Apache updates and their impact on web hosting environments is extensive. Articles and forums discuss how newer versions can introduce compatibility challenges, particularly when older systems or configurations are involved. Many discussions also suggest strategies for minimizing downtime and ensuring smooth transitions during major software updates.
Similar questions
What is a “421 Misdirected Request” error?
How does this error relate to the Apache update?
Why do security patches in Apache cause problems for nginx?
What needs to be added to the nginx configuration to fix the issue?
Where can I find detailed steps to solve this problem?
What is TLS Server Name Indication (SNI)?
Is there a specific version of Plesk where this issue started occurring?
Can this error affect all websites hosted on my server or just some?
Do I need to restart nginx after making changes to the configuration?
Where should I look for more information if I encounter other issues?