Holy Hash!

Security is quality under attack. Hard-won lessons in software security, from someone who built the programs and wrote the standards.

Archive for the ‘unexpected’ tags

9 November 2013

Google bots subversion

There is a lot of truth in saying that every tool can be used by good and by evil. There is no point in blocking the tools themselves as the attacker will turn to new tools and subvert the very familiar tools in unexpected ways. Now Google crawler bots were turned into such a weapon to execute SQL injection attacks against websites chosen by attackers.

it_photo_76483_200x133The discussion of whether Google should or should not do anything about that is interesting but we are not going to talk about that. Instead, think that this is a prime case of a familiar tool that comes back to your website regularly subverted into doing something evil. You did not expect that to happen and you cannot just block the Google from your website. This is a perfect example of a security attack where your application security is the only way to stop the attacker.

The application must be written in such a way that it does not matter whether it is protected by a firewall – you will not always be able to block the attacks with the firewall. The application must also be written so that it withstands an unanticipated attack, something that you were not able to predict in advance would happen. The application must be prepared to ward off things that are not there yet at the time of writing. Secure design and coding cannot be replaced with firewalls and add-on filtering.

Only such securely designed and implemented applications withstand unexpected attacks.

16 February 2013

The art of unexpected

Expecting the unexpected?I am reading through the report of a Google vulnerability on The Reg and laughing. This is a wonderful demonstration of what the attackers do to your systems – they apply the unexpected. The story is always the same. When we build a system, we try to foresee the ways in which it will be used. Then the attackers come and use it in a still unexpected way. So the whole security field can be seen as an attempt to expand the expected and narrow down the unexpected. Strangely, the unexpected is always getting bigger though. And, conversely, the art of being an attacker is an art of unexpected, shrugging off the conventions and expectations and moving into the unknown.

Our task then is to do the impossible, to protect the systems from unexpected and, largely, unexpectable. We do it in a variety of ways but we have to remember that we are on the losing side of the battle, always. There is simply no way to turn all unexpected into expected. So this is the zen of security: protect the unprotectable, expect the unexpectable and keep doing it in spite of the odds.