Lately I’ve been analyzing a .NET binary that was quite interesting. It was a portable binary that shipped without any third-party dependencies. I started looking at the .NET assembly with ILSpy and noticed that there was not that much code that ILSpy found and there were a lot of references to classes/methods that were neither in the classes identified by ILSpy nor were they part of the .NET framework.Continue reading
Hey there, for those of you that roll your eyes when writing the nth Information Disclosure Finding in a report, here is a short story of how such information helped compromising a system.Continue reading
Birk an me basically fully disclosed a 0day in Squirrelmail yesterday. This is a short Q&A to answer the most common questions about the issue to calm you all down a little bit. 😉Continue reading
This is a guest blog post by Salvador Mendoza.
During years, many different researches and attacks against digital and physical payment methods have been discussed. New security techniques and methodologies such as tokenization process attempts to reduce or prevent fraudulent transactions.Continue reading
If you attack someone, they will defend themselves, but if you tickle them, they will eventually crack open. This surprisingly applies to Android apps as well! Therefore, I created AndroTickler, not to test apps against certain attacks or examine them for specific vulnerabilities, which developers would learn to avoid. However, it helps pentesters to analyze and test apps in their own style, but in a faster, easier and more flexible way. AndroTickler is a Swiss-Army-Knife pentesting tool for Android apps. It provides information gathering, static and dynamic analysis features, and also automates actions that pentesters frequently do and highly need during their pentests. In addition, it makes use of the powerful Frida to hook to the app and manipulate it in real-time.Continue reading
Here is a short blog post that explains how you can make your own Man-in-the-Middle (MitM) setup for sniffing the traffic between a SIM card and the backend server. This is NOT a new research but I hope this will help anyone who doesn’t have a telco background to get started to play with mobile data sniffing and fake base stations. This is applicable to many scenarios today as we have so many IoT devices with SIM cards in it that connects to the backend.
In this particular case, I am explaining the simplest scenario where the SIM card is working with 2G and GPRS. You can probably expect me with more articles with 3G, 4G MitM in future. But lets stick to 2G and GPRS for now.
Some time ago, one of our customers contacted us with a special request. For some legitimate reason, they needed to centrally collect certain certificates including their private keys which were distributed across many client systems running Windows and stored in the corresponding user stores. Unfortunately (only in this case, but actually good from a security perspective), the particular private keys were marked non-exportable making a native export in the context of the user impossible. As if this wasn’t enough, the extraction was supposed to be executed in the context of the current user (i.e. without administrative privileges) while not triggering the existing Anti Virus solution at all. Also, the certificates needed to be transferred to some trusted system where they could not be accessed in an unauthorized way. So let’s have a look how we tackled these problems:Continue reading
In one of the last pentests we’ve found an epmd (Erlang port mapper daemon) listening on a target system (tcp/4369). It is used to coordinate distributed erlang instances, but also can lead to a RCE, given one knows the so called “authentication cookie”. Usually, this cookie is located in ~/.erlang.cookie and is generated by erlang at the first start. If not modified or set manually it is a random string [A:Z] with a length of 20 characters. If an attacker gains this cookie, a RCE is quite easy – as I like to describe below.Continue reading
We recently identified a security issue in FireEye AX 5400, that also affected other products. We responsibly disclosed the bug to FireEye and a fix that addresses the issue has been released with version 7.7.7. The fix was also merged into the common core and is available as 8.0.1 for other products (i.e. FireEye EX).
The related release notes can be found here:
FireEye announced to post a 2017 Q3 notice with credit to us, too.Continue reading
The git-shell is a restricted shell maintained by the git developers and is meant to be used as the upstream peer in a git remote session over a ssh tunnel. The basic idea behind this shell is to restrict the allowed commands in a ssh session to the ones required by git which are as follows:
- Receives repository updates from the client.
- Pushes repository updates to the client.
- Pushes a repository archive to the client.
Besides those built-in commands, an administrator can also provide it’s own commands via shell scripts or other executable files. As those are typically completely custom, this post will concentrate on the built-in ones.
Note: This has nothing to do with the also recently fixed vulnerabilities in gitlab  .