Doesn't seem to work with Firefox + NoScript [LWN.net]

Doesn't seem to work with Firefox + NoScript

Posted Sep 3, 2009 15:50 UTC (Thu) by kfiles (subscriber, #11628)
In reply to: Doesn't seem to work with Firefox + NoScript by cesarb
Parent article: What the Internet knows about you

> The hidden image trick is very easy to avoid, just add the following to
> your userContent.css:

> :link, :visited { background-image: none !important }

I've noticed that sites like
http://ha.ckers.org/weird/CSS-history.cgi

are tricker. They attach a background-image to a child of the <a> tag. For example, the following CSS rule:

a:visited span.span0 {
background: url(CSS-history.cgi?xxx);
}

applied to:
<a href="www.google.com">http://www.google.com
<span class="span0">VISITED</span>
</a>

So you'll also need the following in your userContent.css:

:link *, :visited * { background-image: none !important; }

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Doesn't seem to work with Firefox + NoScript

Posted Sep 3, 2009 16:58 UTC (Thu) by cesarb (subscriber, #6266) [Link]

Thanks for that one, now the rule I am using is

:link, :visited, :link *, :visited * { background-image: none !important }

Note that the site you linked to still shows a large red "VISITED", even though it is not logging anything anymore (you have to follow the link below the table to see nothing was actually logged). Which implies there are probably several other ways of bypassing this userContent.css rule (perhaps playing with display: and using a IMG, for instance; I haven't tested).