Ruby + GCM Nonce Reuse: When your language sets you up to fail…
A couple hours ago, Mike Santillana posted to oss-security about a rather interesting find in Ruby’s OpenSSL library; in this case, the flaw is subtle – so much so that it’s unlikely that anyone would notice it, and it’s a matter of a seemingly insignificant choice that determines if your code is affected. When performing AES-GCM encryption, if you set the key first, then the IV, and you are fine – set the IV first, you’re in trouble.
Read more…Testing for SWEET32 with YAWAST
Testing for SWEET32 isn’t simple – when the vulnerability was announced, some argued that the best solution was to assume that if a TLS server supported any of the 3DES cipher suites, consider it vulnerable. The problem is, it’s not that simple. On my employer’s corporate blog, I wrote about practical advice for dealing with SWEET32 – and pointed out that there are ways around the vulnerability, and some are quite simple.
Read more…Developers: Placing Trust in Strangers
Much has been said, especially recently, about that mess of dependencies that modern applications have – and for those of us working in application security, there is good reason to be concerned about how these dependencies are being handled. While working on YAWAST, I was adding a new feature, and as a result, I needed a new dependency – ssllabs.rb. While most Ruby dependencies are delivered via Gems, ssllabs.rb is a little different – it pulls directly from Github:
Read more…Threat Modeling for Applications
Whether you are running a bug bounty, or just want a useful way to classify the severity of security issues, it’s important to have a threat-model for your application. There are many different types of attackers, with different capabilities. If you haven’t defined the attackers you are concerned about, and how you deal with them – you can’t accurately define just how critical an issue is. There are many different views on threat models; I’m going to talk about a simple form that’s quick and easy to define.
Read more…When Hashing isn’t Hashing
Anyone working in application security has found themselves saying something like this a thousand times: “always hash passwords with a secure password hashing function.” I’ve said this phrase at nearly all of the developer events I’ve spoken at, it’s become a mantra of sorts for many of us that try to improve the security of applications. We tell developers to hash passwords, then we have to qualify it to explain that it isn’t normal hashing.
Read more…Seamless Phishing
Phishing attacks are a fact of life, especially for users of the largest sites – Facebook being the most common I’m seeing today. Pretty much everybody, from the SEC to antivirus companies have published guides on what users should do to avoid phishing – so I picked one at random and pulled out the key points: 1). Always check the link, which you are going to open. If it has some spelling issues, take a double-take to be sure — fraudsters can try to push on a fake page to you.
Read more…PL/SQL Developer: HTTP to Command Execution
While looking into PL/SQL Developer – a very popular tool for working with Oracle databases, to see how it encrypts passwords I noticed something interesting. When testing Windows applications, I make it a habit to have Fiddler running, to see if there is any interesting traffic – and in this case, there certainly was. PL/SQL Developer has an update mechanism which retrieves a file containing information about available updates to PL/SQL Developer and other components; this file is retrieved via HTTP, meaning that an attacker in a privileged network position could modify this file.
Read more…Crypto Crisis: Fear over Freedom
Yesterday, President Obama spoke at SXSW on topics including the oft-discussed fight between Apple and the FBI – what he called for, while more thoughtful than some of the other comments that we have been hearing from Washington, was still tragically misinformed. He repeated the call for a compromise, and by compromise, he meant backdoors. Here, I feel I must paraphrase one of my favorite authors to properly express the magnitude of what’s being discussed here:
Read more…PL/SQL Developer: Nonexistent Encryption
(See here for another issue discovered during this research; Updates over HTTP & Command Execution.) PL/SQL Developer by Allround Automations has an option to store the user’s logon history with passwords – the passwords are encrypted with a proprietary algorithm. At this point, you should know how this is going to go. For those that don’t know, PL/SQL Developer is a tool for developers and database administrators to access Oracle – an essential tool in many enterprise environments.
Read more…Rance, Goodbye Friend
If you never had the oppertunity to meet Rance, known as David Jones to some, you don’t know what a friend you missed. Today, you lost the chance to find out. He was truly something special – one of the most genuine, kind, and caring people I’ve ever met. I met him at the first security conference I ever attended – while I had always been somewhat involved with security work, I really wasn’t a member of the community, I was an outsider, and every word I said, I was painfully aware of that.
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About Me
Security researcher, engineer and software developer with more than 20 years of experience.
Work: I primarily focus on application security, usable security, secure communications, and cryptography. I build and lead strong and dynamic teams, who cover all facets of security and privacy.
Writing: I write about my research, security in general, development and software design, and leadership through my blog, essays, and various publications. I also engage in some creating writing when I can.
Photography: I am a purist fine art photographer, working primarily in black & white, and focused on sharing new perspectives of the world. Limited edition prints of my work are available on my online gallery. I also have a background in photojournalism, and volunteer in this field when I can.