340875 - When Flash adds a custom header request of "User-Agent", Firefox includes one too

Status: RESOLVED INVALID

(Core Graveyard :: Plug-ins, defect)

Description

[David Lollar]

User-Agent:       Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.1)
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.4) Gecko/20060508 Firefox/1.5.0.4

Flash Player allows you to add custom headers to your URL request for loading data. If you add one for "User-Agent", the header is added to the request, along with Firefox's header for "User-Agent". This results in the request being sent with two "User-Agent" headers, which leads the server to respond that the request is malformed and reject it.

Reproducible: Always

Steps to Reproduce:
1. Include a SWF file in your Firefox page that adds a request header with "User-Agent"
2. Open the HTML page in Firefox
3. Trace the request header sent out

Actual Results:  
The header will have two "User-Agent" strings.
Ex:
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.4) Gecko/20060508 Firefox/1.5.0.4\r\n
User-Agent: Added by user in Flash\r\n

Expected Results:  
There should be only one User-Agent string

Comment 1

[Frank Wein [:mcsmurf]]

Could you possibly attach a Flash example which sends such a request (to any server you like, just as a example)?

Comment 2

[David Lollar]

Attachment: swf to illustrate problem

Comment 3

[David Lollar]

Attachment: HTML to open the attached SWF

Open the attached SWF in this HTML page

Comment 4

[David Lollar]

I found that the custom User-Agent string is only added when data is included via POST method with the request. If POST is not used, Firefox does not include the custom User-Agent string in the header. Instead, it cuts the custom User-Agent and only sends its own.

Comment 5

[Wayne Mery (:wsmwk)]

Do you still see this problem using latest version of Firefox and Flash (10)?

If you do, please comment.
If you do not see the problem, please close the bug - don't use resolution=FIXED, change resolution to:
- INVALID if you believe the problem was flash player
- WORKSFORME if you believe the problem was in Firefox
- INCOMPLETE if it is impossible to test (url or testcase is gone)

Comment 6

[David Lollar]

Closing bug as invalid -- ActionScript does not allow setting "User-Agent", so this bug no longer applies.