Forum Discussion

Cirrostratus

Oct 05, 2021

Can't upload msg file - ASM block

WAF block my request due to " attack signature detected" when try to upload msg file , and the Context : HTTP Request Body Unparsed Payload. the request is look like this : Content-Type: multipa...

Daniel_Wolf
Oct 06, 2021
This looks correct, though I don't have any lab where I could test this at the moment.
Your configuration would apply anytime the Content-Type header value is multipart/form-data.
The Request Header Value allows wildcards. You could try to narrow down to Do Nothing only for .msg files by testing this combination:

Request Header Name : Content-Disposition
Request Header Value : form-data; name="*.msg"; filename="*.msg"
Request Body Handling : Do Nothing

EDIT: A word of caution. You should consider to what risk you are exposing your application when not checking these uploads.

Nikoolayy1

MVP

Feb 22, 2023

The strange thing is that I as well may test this solution as I have a query paramater in a POST request (strange yup !) that is for file upload with Content-Type: application/xxxx but F5 ASM/AWAF still is trying to inspect the body and thinks that the file body is another Parameter name and I get "Failed to convert character" and "HTTP protocol compliance failed", so making the query parameter of type file upload just can't stop the F5 to try to understand the body and try to check it 😁