Why origin and/or referer values are null?

[Eliza]

Hi Fiddler Team,

 

I'm conducting an analysis on origin referer and have 4 scenarios:

1. No Origin, No Referer

 

2. No Origin, Referer Present

 

3. Origin Present, Referer Missing

 

4. Origin Present, Referer Present

 

Can you please help me to understand why origin and / or referer are missing (scenarios 1-3)?

 

Thanks!

[Nick Iliev]

Hello Eliza,

 

There may be specific reasons for the observed results, but common explanations exist for when the Origin is null or when the Referer is missing.

Check the following sources:

https://wiki.mozilla.org/Security/Origin - refer to the table called "When Origin is served (and when it is "null")"

https://www.rfc-editor.org/rfc/rfc2616#section-15.1.3 - see the below quote from the linked source

  Clients SHOULD NOT include a Referer header field in a (non-secure)
   HTTP request if the referring page was transferred with a secure
   protocol.

 

Regards,
Nick Iliev
Progress Telerik