HTTP 500 response with access gateway apache error code AH02429: Response header name 'text/html' contains invalid characters

Products

• SITEMINDER

Issue/Introduction

A new back end application is onboarded to the SSO Access Gateway via proxy, but it is receiving HTTP 500 responses upon request.

Browser trace shows error 500, which matches with apache access log error.

Apache access log:

x.x.x.x - - [dd/mmm/yyyy:19:30:59 +0000] 0 433881 "POST /example/resource HTTP/1.1" 500 2676 "Root=1-xxxxxxxx-xxxxxxxxxxxxxxxxxxxxxxxx"

Apache error log:

[Tue mmm dd 19:31:00.307407 yyyy] [http:error] [pid 15268:tid 140619259287104] [client x.x.x.x:57682] AH02429: Response header name 'text/html' contains invalid characters, aborting request, referer: https://accessgateway.example.com/example/resource

Cause

Web agent log and trace log has no error, and in fact, both user auth and az calls went through successfully.

Even proxy is completed with HTTP response 200, not 500.

SiteMinder is NOT the cause of problem.

Resolution

Error "AH02429: Response header name 'text/html' contains invalid characters", this is generic apache error. Not uniquely to SiteMinder.

It means the back end app sends response as literally "text/html: some_value" instead of "Content-Type: text/html".

Apache expects something like "Content-Type: text/html" as legit header.

Back end application needs to be fixed.