During code reviews we often see developers using weak RNGs like math.random() to generate cryptographic secrets. We think it is commonly known that weak random number generators (RNG) must not be used for any kind of secret and recommend using secure alternatives. I explicitly did not state a specific language yet, because basically every language offers both weak and strong RNGs.
So I asked myself: What if I use a weak RNG to generate a secret? Is it possible to recover the secret from some derived value, like a hash?
As you probably know we perform research on a regular basis at ERNW. This post is the first entry on our – Benjamin’s and Pascal’s – research diary. You might already have seen Oliver’s post on setting up an research environment or Brian’s posts on IoT botnets (here and here). With that in mind we want to take a look at one of the market leaders for network camera equipment: AXIS.
At first we’d like to give a quick overview of our research objects. We bought two cameras, an AXIS M1033-W and an AXIS M3005-V. The M1033’s description states that it is for “small business, hotels, residences and more”. The M3005 has a typical dome design and was actually seen in some customer environments during projects this year.
Yesterday the US-CERT released a Technical Alert (TA16-144A) about the recently found WPAD Name Collision Vulnerability. We will give you a summary about the vulnerability as well as the basic mechanisms here.
WPAD
The Web Proxy Auto-Discovery Protocol is used to auto-configure the proxy for web browsers. So when joining the according network the browser can use DHCP and DNS methods to find a specific configuration file (typically named wpad.dat), which is loaded and applied to the browser’s settings. Therefore, there is no need to configure each browser in your environment individually/manually.
Hello everybody and welcome to the second part of our 32C3 recap!
In case you didn’t see the first part, make sure to check it out 😉
Logjam
by **Nadia Heninger & Alex Halderman
**Video | Slides
This talk was held by Nadia Heninger and Alex Halderman on the second day of the congress. Both work in academic and the field of cryptology. They talked about the “Logjam”-Attack they and several colleagues discovered and published in may of 2014. They started their talk by explaining how they uncovered the vulnerability which was quite interesting since Logjam was no breaking news anymore. And well it was inspired by the congress of the year before, 31C3. The research was conducted because they got curious how the NSA might be able to decrypt VPN traffic as stated by Jacob Applebaum and Laura Poitras in their “reconstructing narratives” talk.
Some of you might use WebEx in their daily life. And some of you might use Linux (as I and many of us do). However, this combination often results in issues with your PC’s sound or microphone use in a WebEx session.
The problem here is that WebEx won’t run as intended with Firefox and JRE x64. But the solution is quite easy! Use the x86-versions of each.
Lately we had to analyze QR-Codes in a pentest. Those held some random data which was used as a token for login and we wanted to know if that data was really random.
If you ever worked with the Burp Suite you may know the Burp Sequencer, which offers some statistical analysis regarding the randomness of tokens which appear in requests (you just have to tell Burp what or where the token is). In our case the QR-Code was delivered as an inline-image in HTML to the browser, like this: