Archive for the Flash Category

Proof of concept:

  1. Disable IE7's Protected Mode
  2. ...

OK, I was just joking.

I'm confident this blog post is a joke as well.
After all, its author is a MVP...

If you're a FlashBlock user, you may feel outraged by being brutally rickrolled this way, but you need to know that it could happen at any moment.

No special trick, just a Youtube movie embedding through a plain


HTML element. Examine the source code if you don't believe it:

<object width="300" height="242" data=""> </object>

Not a big deal, really, if you consider FlashBlock a "noise reducer": it does a great job, in facts, working almost always.

A bit more worrisome, though, if you used to believe FlashBlock could improve your security against Flash vulnerabilities. Your next surprise video star may be way more malicious than Trojan.SWF.Astley...

To be fair, you would be in good company:

If they just looked at FlashBlock's FAQ, they would have found that the word "security" is never mentioned: a testament both to the good faith of the developers, who honestly advertise FlashBlock as an excellent annoyance blocker rather than a security enhancement, and to the superficiality of some advices.

Dancho is especially inexcusable, since he's the only one forgetting to mention NoScript, which features similar flash-blocking capabilities but, being developed with security as its main focus, is immune from this and other possible circumventions and, more important, would regard even the most exotic unblockable edge case as a serious bug to be fixed as soon as possible.

Oops, I couldn't block my own rant :)

Did you know crossdomain.xml, introduced by Adobe Flash to allow cross-domain requests, is now supported by Java?

A similar mechanism is being standardized for XMLHttpRequest, and had been implemented in an early Firefox 3 beta (some extra work for your friendly neighborhood NS-Man), but ultimately dropped later in the development cycle...

Some minutes after I published my post about the Flash unpatched vulnerability being exploited through mass SQL injections, popups of this kind started flying all over my notebook's desktop:
AVG Notification: Threat Detected in a Cache File
Since the "virus" was reported to be in my Firefox cache, and since Firefox has not the bad habit of randomly open cached files for execution, I guessed this "threat" was relatively harmless and AVG was just over-reacting to the mere "open for reading" action.
In facts, all my attempts to inspect the offending file using an hexadecimal editor were frustrated with "Access Denied" errors, and AVG on its side refused to give me any argumented detail about this alert.

Hence I typed


in my awesome bar and quickly found a file matching the size of the "menace": it was

, i.e. the RSS feed of Ronald van den Heetkamp's "Hacker Webzine"...

So, was just a mere van den Heetkamp stink enough to scare the hell out of my cute (and frankly, absolutely virginal) anti-virus?
Actually the most likely culprit is Ronald's latest article about the hot topic of the day: since he likes to feature generous portions of source code extracted from infected sites, a signature-based engine like AVG have no choice but going wild.

Dear anti-virus vendors, can we have a "Relax, I use Firefox + NoScript" Ronald-friendly option, please?

Yesterday Symantec elevated its ThreatCon rating as a response to an infection involving about 20,000 web pages (250,000 according to other sources), and probably still actively spreading through an automated SQL injection.

The main news is that this time an apparently unpatched vulnerability affecting Adobe Flash Player is being exploited, making the attack on end-users effectively cross-browser and potentially cross-platform:

The attack uses multiple layers of SWF redirection and generates URLs designed to target specific Flash version and browser combinations, supporting both Internet Explorer and Firefox.

The Adobe Product Security Incident Response Team reports of being aware of this problem and cooperating with the antivirus company for a precise assessment.

In the meanwhile, according to Symantec, you should:

Avoid browsing to untrustworthy sites. Consider disabling or uninstalling Flash until patches are available. Deploy script-blocking mechanisms, such as NoScript for Firefox, to explicitly prevent SWFs from loading on all but explicitly trusted sites. Temporarily set the kill bit on CLSID d27cdb6e-ae6d-11cf-96b8-444553540000 until patches availability is confirmed.

Additional notes for NoScript users

Since the offending SWF files are served from external ad-hoc Chinese domains, (, and at this moment,very unlikely to be in your whitelist), even if a trusted site was infected you should still be protected.

However, if you want maximum protection, it's a good time to check NoScript Options|Plugins|Apply these restrictions to trusted sites as well.
This option turns NoScript in an effective security-oriented replacement of the FlashBlock extension, working also with Java, Silverlight and other potentially vulnerable plugins such as QuickTime.
All the active embedded content pieces, no matter where they come from, will be blocked preemptively and you will be able to load them selectively by clicking on visual placeholders.


(from PSIRT's blog):

This exploit appears to be taking advantage of a known vulnerability, reported by Mark Dowd of the ISS X-Force and wushi of team509, that was resolved in Flash Player We strongly encourage everyone to download and install the latest Flash Player update,

Since the currently exploited vulnerability appears to be patched, but the attacking vector explicitly tests for the player and can perform dynamic redirects, I'd obviously upgrade but still stay on the cautious side, deploying preemptive countermeasures just in case they're saving the real zero-day for a second weave...

Bad Behavior has blocked 965 access attempts in the last 7 days.