You can install the
apache2 package from the Ubuntu software repositories. Updated packages usually contain important bug and security fixes. When an updated version is released, install it as quickly as possible to keep your system secure.
Check the Apache site for security reports. Browse to http://httpd.apache.org/security_report.html for links to security vulnerabilities for Apache 1.3, 2.0, 2.2, and 2.4. Subscribe to a support list or browse through up-to-date archives of all Apache mailing lists at http://httpd.apache.org/mail/ (for various articles) or http://httpd.apache.org/lists.html (for comprehensive and organized archives).
You should be wary of installing experimental packages, ...