Code injection, XSS with Javascript
Hello
Since several year I am dealing with browser problems. There are insulting adds appearing on the screen, there are strange network problems (I have to confirm several times that I am being human and not a bot (picture 1)), When I open certain websites there is nothing at all displayed (picture 2). Or even some variables are changed (through DOM ?). Here is an example, I was looking for a new flat at homegate.ch. I have set the rent limit to 1400 .-, and hit the search button. The result which was displayed is this (picture 3). I get flat results with a rent of 1790.- or even 1950.-. But actually I know those flats have a rent less than 1400.-. I found out, that there is a factor of lets say 1.45. If you divide the rent of the search results through 1.45, you get the real rent, this is true for all search results. My firefox settings are very security focused (HTTPS-only enabled, DNS over HTTPS, block cross site cookies,...), I am using a vpn client to connect to the internet. I guess the problem has something to do with code injection, XSS attack through JavaScript. But can t tell how, I guess cookies or session Token are involved in this attack. Can you please give me an advice, how to solve this annoying problem? Thanks in Advance
kind regards Stefan
All Replies (2)
Does this still happen if you disable the VPN and use a direct connection ? What exit point (country) is your VPN using as it could be possible that another currency is used despite the CHF label?
Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Settings), click the padlock icon (Clear cookies and site data) for the domain in the selected tab.
"Remove the Cookies" for websites that cause problems:
- Settings -> Privacy & Security
Cookies and Site Data: "Manage Data"
"Clear the Cache":
- Settings -> Privacy & Security
Cookies and Site Data -> Clear Data -> [X] Cached Web Content -> Clear
- https://support.mozilla.org/en-US/kb/clear-cookies-and-site-data-firefox
- https://support.mozilla.org/en-US/kb/how-clear-firefox-cache
Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or if userChrome.css/userContent.css is causing the problem.
- switch to the Default System theme: "3-bar" menu button or Tools -> Add-ons -> Themes
- do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window
Thank you for your reply. I have tried your suggestions. Actually the problems are still there when I clear cookies and site data, but are gone when I clear cookies and site data and connect without VPN to the internet. I was able to load the website which I wasn`t able to load before, and the rent are not changed anymore. Not sure if this is the solution to my problems, since there are good reasons to use a VPN client. In my opinion this problem has nothing to do with geoblocking or location of the exit point, because a website like roche.com should be accessible from everywhere, also the rent should not change due to the location from where you connect since the currency label didn`t change. My exit point are the netherlands. In my opinion the currency label depends on the location of the flat, but not the location form where you connect. Have you further suggestions? Thanks to your inputs I made some progress.
Kind regards Stefan
Modified by stefan
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