Last year I discovered an unusual but useful method for writing web application code: non-alphanumeric JavaScript. This technique has been pioneered by several script ninjas on the hackers forum sla.ckers.org and lets you write scripts without directly using letters or numbers. Application filters or sandboxes may catch typical attacks by monitoring for requests such as “document.cookie,” but they may let non-alphanumeric code slip through. How does it work? First, you can use blank objects or arrays to generate basic values. For instance, +[] evaluates to the number zero, while !{} returns the boolean value false. You can also combine these simple results to create strings, such as [!{}]+[+[]] == “false0”. By treating these strings as arrays, we can grab individual[…]
Category: Tutorial Tuesday
Each Tuesday, Security Musings features a topic to help educate our readers about security.
My article, “Maddening Methods: Fundamentals of Risk Assessment and Analysis,” was published in the July 2010 edition of The ISSA Journal. It covers some of the key concerns around risk assessment today, including addressing common arguments posited against risk assessments and risk management. From the abstract: Considerable confusion exists in the security industry around the effectiveness of risk assessment and analysis methodologies. Points of contention often focus on specific attributes of a given method, such as data quality, statistical analysis, or a qualitative versus quantitative approach. There are reasonable, viable answers to these points of contention that resolve most of these concerns. I hope that you’ll find this piece informative and enjoyable.
I don’t know if it’s PCI compliance fever season or what, but I’ve been asked a lot about “weak SSL ciphers” lately. Mostly, having to do with “what the heck are those anyway?” If you don’t have a decent grasp of SSL, start with my previous article on SSL. If you think you do, stay with me for a bit 🙂 Let’s start with what ciphers are. Ciphers are the algorithms used to do some kind of cryptography – either encryption or hashing. Well known ciphers you’ve probably heard of are RSA, 3DES, AES, Blowfish, and SHA1. SSL Ciphers are the set of ciphers that are used for all parts of the SSL negotiation – and remember there are several[…]
Applications, specifically web applications, often rely on e-mail to send out error reports to administrators and developers. While e-mail can be somewhat unreliable in terms of delivering messages in a timely fashion, it is also insecure. If your application’s error reports contain identifying information about users or sensitive details about your code and what made it break, you should be delivering these messages using encrypted S/MIME e-mail. This tutorial will show how to send an encrypted message from a .NET application.
In celebration of Facebook’s recent privacy control revamp, I present a very informative tutorial video from the Electronic Frontier Foundation that gives a brief rundown of the changes, the highs, and the lows. This might also be something beneficial to share with friends or relatives on Facebook who may not be in-the-know about the increased focus on privacy control in social networking and social media. Enjoy:
PDF files have become commonplace on the Internet and in the business world, but they have also become favorite tools for attackers to deliver malicious payloads. While some problems may be mitigated by using an alternative PDF reader, many people have little choice but to use the standard Adobe Reader. In that situation, you can help protect yourself from many PDF-based attacks by following a few basic steps. Make sure you have an up-to-date anti-malware program installed and running with automatic download of new virus definitions. Older tools may not scan for recent PDF-based threats. Make sure you have the latest version of Adobe Reader. Enable automatic updates by opening Reader and choosing Edit > Preferences > Updater. Adobe regularly[…]