Problems processing large responses

[roelstorms]

I discovered this issue during a pentest where a large js file is downloaded from the server. (length 2885688 bytes). I noticed that the browser kept waiting for a response. When issuing the same request from the repeater, the response was returned successfully. Without the proxy, the js file could also be retrieved via the browser.

Inspecting the issue with Wireshark showed me that the request was issued from Burp to the server and the response was received by my machine and thus by burp. After looking at Burp configs I decided to disable all extensions. This narrowed the problem down to this particular extension. I don't know why the extension inhibits the response from reaching the browser through the proxy. If I have some time I will try to recreate the issue with the error output from Burp.

[pathetiq]

Thanks for this, if you can provide the file or a similar one that create the problem I will look it up. JS file are not supposed to be analysed and maybe a bad condition make the extension analyse the file and hang because of the size, etc.

Thanks again for reporting that and I'll wait for more detail.

[roelstorms]

I had the problem with kendo where they followed "how to do it wrong" from this "tutorial". http://developer.telerik.com/featured/using-ui-libraries-without-the-bloat/