Archive for October 2nd, 2008

As I hinted in my original clickjacking article and confirmed in my follow-up about protecting other browsers from clickjacking, specific anti-clickjacking countermeasures are included in latest NoScript development builds, enabled by default, and completely independent from frame blocking.

Specifically, since 1.8.1.7 (released past Friday), embedded objects of any kind are forcibly made opaque if placed on a non-whitelisted page, giving user a clear view on what he's about to click.
A further protection layer, automatically disabling any user interaction with partially obstructed documents (similar in concept to Zalewski's preferred proposal), will go in a stable release by the end of this week, but current development builds are already safe and good enough for general consumption, so I recommend upgrading now (update) is available in NoScript 1.8.2 and above.

Starting this fresh development line, rather than sitting on the serendipity of old NoScript features being able to prevent known forms of clickjacking, proved to be a very wise thing to do.
In facts, both RSnake and Ronald during the last two days found frame blocking work-arounds. RSnake in particular, being a NoScript user himself, has been so kind to do responsible disclosure, giving me also a lot of constructive feedback about the alternate mitigation ideas I was developing.

I must be grateful to Ronald as well, because he -- even if in a less cooperative way -- underlined a conceptual weakness in IFRAME blocking (since OBJECTs can behave just like IFRAMEs, they should be blocked according to the very same criteria), but I have to rectify this statement from his public disclosure post:

The latest version of NoScript allows it's users to block iframes in order to protect themselves from "Clickjacking".

NoScript has been capable of blocking IFRAMEs for a long time: this feature had been introduced mainly to make Gareth Heyes happy, more than one year ago. As often observed with NoScript, an old feature happens to be effective against new threats.
Unfortunately, bugs happen too and IFRAME blocking not being applied to all the frame-like elements is what I do consider a bug. This one will be fixed in the automatic stable update you're going to receive in a few days, but in the meanwhile is already fixed; you can enjoy the new specific clickjacking protection, no matter if you block frames or not, by simply upgrading to NoScript 1.8.1.8 or above.

Update Oct 2nd, afternoon

The frame/object bug has already been fixed in 1.8.1.9, one more reason to upgrade.

Update Oct 7th

NoScript 1.8.2 is finally out, featuring the brand new exclusive ClearClick technology against Clickjacking. Upgrade now!

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