Unexpected Deserialization pt.1 - JMS

On a recent engagement our task was to assess the security of a service built on IBM Integration Bus, an integration platform for Java Messaging Services. These scary looking enterprise buzzwords usually hide systems of different complexities connected with Message Queues. Since getting arbitrary test data in and out of...

8 minute read

Decrypting and analyzing HTTPS traffic without MITM

Sniffing plaintext network traffic between apps and their backend APIs is an important step for pentesters to learn about how they interact. In this blog post, we’ll introduce a method to simplify getting our hands on plaintext messages sent between apps ran on our attacker-controlled devices and the API, and...

7 minute read

Uninitialized Memory Disclosures in Web Applications

While we at Silent Signal are strong believers in human creativity when it comes to finding new, or unusual vulnerabilities, we’re also constantly looking for ways to transform our experience into automated tools that can reliably and efficiently detect already known bug classes. The discovery of CVE-2019-6976 – an uninitialized...

3 minute read

Unix-style approach to web application testing

SANS Institute accepted my GWAPT Gold Paper about Unix-style approach to web application testing, the paper is now published in the Reading Room. The paper introduces several problems I’ve been facing while testing web applications, which converged in a common direction. Burp Suite is known by most and used by...

1 minute read

Wide open banking: PSD2 and us

With the advent of PSD2 APIs, we had the opportunity to test some of them upon request from our clients. Although internet-facing APIs were already a thing thanks to smartphone apps, it seems that regulatory requirements and 3-way setups (customer, bank, provider) led to some surprises. Here are some of...

4 minute read

Patching Android apps: what could possibly go wrong

Many tools are timeless: a quality screwdriver will work in ten years just as fine as yesterday. Reverse engineering tools, on the other hand need constant maintenance as the technology we try to inspect with them is a moving target. We’ll show you how just a simple exercise in Android...

5 minute read

Evading Cisco AnyConnect blocking LAN connections

Some VPNs allow split tunneling, however, Cisco AnyConnect and many other solutions offer a way for network administrators to forbid this. When that happens, connecting to the VPN seals off the client from the rest of the LAN. As it turns out, breaking this seal is not that hard, which...

5 minute read