The ApacheErrorDocument directive should be set correctly for HTTP 401 errors. (1) message/document (1) Apache configuration file: 'ErrorDocument 401' directive L1 11. Web Server Software Obfuscation General Directives p17 CIS Apache Benchmark for Unix v1.7 For Apache Versions 1.3 and 2.0 CIS 2007-07-01 Version 1.7 Prose (PDF)