Author Archives: Shezaf

About Shezaf

Ofer Shezaf is a senior director for cyber security at Varonis. Ofer works closely with the Varonis product team to ensure that the Varonis products continue to address new and upcoming security threats. Before joining Varonis, Ofer led security research at HP and before that in Israel's cyber warfare department. As an internationally recognized security expert, Ofer is an OWASP (Open Web Application Security Project) leader and the founder of the OWASP Israeli chapter. Some community projects Ofer has led are the OWASP ModSecurity Core Rule Set Project and the WASC Web Application Firewall Evaluation Criteria project. Ofer spoke at numerous conferences including BlackHat, RSA, HitInTheBox and OWASP AppSec.

Keeping Ahead of the Hackers

While my posts are typically more focused, Andy Green who is managing digital content at Varonis, thought it would be a good idea to share thoughts around the evolution of the threat landscape over the years: how did attack techniques evolve, the changes brought by the dark web and the economics of hacking, what we, the defenders are doing – wrong or right – and what we should do better.

So if you are into some techno-philosophical thoughts about cybersecurity, here it is:

Brute Force: Anatomy of an Attack

I am back to blogging, but my blog posts now appear on the Varonis blog. I will keep publishing links to those posts here for my loyal followers.

This time:

The media coverage of NotPetya has hidden what might have been a more significant attack: a brute force attack on the UK Parliament.  While for many it was simply fertile ground for Twitter Brexit jokes, an attack like this that targets a significant government body is a reminder that brute force remains a common threat to be addressed.

It also raises important questions as to how such an attack could have happened in the first place.  These issues do suggest that we need to look deeper into this important, but often misunderstood type of attack.

Read more…

Bobby Tables real life coutnterpart

If you are a member of the application security community, you are bound to know this hilarious xkcd cartoon. It is so good that it found its way to non-expert circles. I once got it physically framed as a birthday present from friends.

tables

Like most of you, I though that this is a great way to explain SQL injection. For most of us, this is what it is. For a few, it is a real life problem

My dear friend Or Katz published an even more hilarious blog post outlining the challenges of someone who happens to have a first name which is an SQL keyword. His post is also a very good discussion of the use, or rather abuse, of signatures for web application security. A great and worthwhile read.

Anniversary to the ModSecurity Core Rule Set celebrated with a new major release

I have a very warm place reserved for the ModSecurity Core Rule Set (CRS). I created it a decade ago. Actually the first release in the readme file, labeled 1.1, is dated to October 2006, so this is an anniversary. And what a great present I got for the Anniversary from Chaim Sanders, Walter Hop and my dear friend Christian Folini: a brand new major release!

If you don’t know what the CRS is, a short introduction is due. Continue reading

The WAF Guidebook: What is a Web Application Firewall?

Simply put, Web Application Firewalls are security controls designed to provide the best automated operational protection for HTTP applications, whether web based on mobile. What is “the best” protection, or even “sufficient protection” is not a simple question.  As a result there is a spectrum of solutions for protecting web applications with varying quality and functionality. Which one can call itself a web application firewall is not an easy question to answer.

Probably the only way to define a web application firewall is to list the key features common to web application firewalls uniquely suited for protecting web and mobile applications and which would differentiate than other operational security controls such as intrusion prevention systems and network firewalls. The following sections touch on those key features of WAFs. A fuller discussion of the features will follow in later posts. Continue reading

Sorting out web automation attacks

If anything makes  web applications security different, and more interesting, than traditional information security, those are threats to the application logic, i.e. attacks that abuse legitimate functionality. Such attacks often raise legal and ethical questions: if this is legitimate functionality, can it be an attack? Ethical questions a side, there is no question that click fraud, scraping and comment spam cause real pain and financial damage to web site owners.

The new OWASP automated threat handbook tries to sort out this field and define an ontology for web automation attacks and for countermeasures.

My own presentation on the topic takes a different approach: there is no real dividing line between valid and malicious automation. It is a continuum. I scored each such automation technique for “obviousness”, i.e. how clear it would be that this is automated and not and for maliciousness.  Based on the scores I split the techniques into obviously malicious, accepted and borderline. So for example, given a 1-5 scale (1 being not obvious/not malicious, 5 being obvious/malicious):

  • “Auction sniping” gets 2 for obviousness and 3 for maliciousness – which makes it borderline.
  • “Web spam” 3 for obviousness and 4 for maliciousness – the extra points puts it in the malicious category.
  • At the edges, Blind SQL injection gets 5 and 5 (so it is extra malicious) while comparative shopping gets 1 for maliciousness as it became a standard in the industry. Which does not imply the “attacked” web site is not negatively impacted.

Read the presentation to get the scored for all of them and learn what “Queue Jumping”, “auction sniping” and “web spam” are!