I've unset the access restrictions for this task in Phabricator as I don't see any security issue here.

When did this problem start?

I assume this is about https://fa.wikinews.org/wiki/ویژه:تغییرات_اخیر
(Steps to reproduce are always very welcome. :)

https://fa.wikinews.org/wiki/%D9%88%DB%8C%DA%98%D9%87:%D8%AA%D8%BA%DB%8C%DB%8C%D8%B1%D8%A7%D8%AA_%D8%A7%D8%AE%DB%8C%D8%B1?debug=true works for me.

$:andre\> wget https://fa.wikinews.org/wiki/%D9%88%DB%8C%DA%98%D9%87:%D8%AA%D8%BA%DB%8C%DB%8C%D8%B1%D8%A7%D8%AA_%D8%A7%D8%AE%DB%8C%D8%B1
Connecting to fa.wikinews.org (fa.wikinews.org)|91.198.174.192|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 0 [text/html]

This started some hours ago, and yes any appending query works.

I looked at this a bit yesterday and it seemed that the Varnish servers has cached an empty page for this URL. Appending a query string was bypassing the Varnish cache and fetching the page directly from the backend servers.

I just checked and the page is rendering as expected to both authenticated and unauthenticated users again without URL manipulation.

@Mjbmr are you still seeing this issue on any pages?

The issue was resolved right after my last comment but it was odd. so please make sure it won't happen again 'cause people mostly won't append anything to URL and they blame it on sysops.

@bd808 Can you give me a little bit more information on what happened that day?

In T78776#1023257, @Mjbmr wrote:

@bd808 Can you give me a little bit more information on what happened that day?

I don't remember any specifics beyond what I wrote on 2014-12-18. The page without additional url parameters was returning with http "X-Cache" headers that indicated a varnish cache hit. The next day the content was correct.

Testing today with curl -v https://fa.wikinews.org/wiki/%D9%88%DB%8C%DA%98%D9%87:%D8%AA%D8%BA%DB%8C%DB%8C%D8%B1%D8%A7%D8%AA_%D8%A7%D8%AE%DB%8C%D8%B1 shows headers indicating that varnish is not caching the page:

< HTTP/1.1 200 OK
< Server: nginx/1.1.19
< Date: Sun, 08 Feb 2015 22:02:28 GMT
< Content-Type: text/html; charset=UTF-8
< Transfer-Encoding: chunked
< Connection: keep-alive
< X-Content-Type-Options: nosniff
< X-Powered-By: HHVM/3.3.1
< Content-language: fa
< X-UA-Compatible: IE=Edge
< X-Frame-Options: DENY
< Vary: Accept-Encoding,Cookie
< X-Varnish: 2999771116, 2495361043, 2368179464
< Via: 1.1 varnish, 1.1 varnish, 1.1 varnish
< Age: 0
< X-Cache: cp1066 miss (0), cp4008 miss (0), cp4009 frontend miss (0)
< Cache-Control: private, s-maxage=0, max-age=0, must-revalidate