Inside Xerox WorkCentre: Two Unauthenticated RCEs

Every organization has printers. Sometimes, there are Xerox WorkCentre among them, large machines that can weigh more than 100 kilos or 220 lbs.

In this writeup, I will cover two unauthenticated RCE vulnerabilities that I discovered in these printers. Next, I’ll provide a checklist for protecting your printers against attacks.

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Getting XXE in Web Browsers using ChatGPT

A year ago, I wondered what a malicious page with disabled JavaScript could do.

I knew that SVG, which is based on XML, and XML itself could be complex and allow file access. Is the Same Origin Policy (SOP) correctly implemented for all possible XML and SVG syntaxes? Is access through the file:// protocol properly handled?

Since I was too lazy to read the documentation, I started generating examples using ChatGPT.

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Android Jetpack Navigation: Deep Links Handling Exploitation

The class available in Android allows creating parts of application UI (so-called fragments). Each fragment has its own layout, lifecycle, and event handlers. Fragments can be built into activities or displayed within other fragments, which lends flexibility and modularity to app design.

Android IPC (inter-process communication) allows a third-party app to open activities exported from another app, but it does not allow it to open a fragment. To be able to open a fragment, the app under attack needs to process an incoming intent, and only then will the relevant fragment open, depending on the incoming data. In other words, it is the developer that defines which fragments to make available to a third-party app and implements the relevant handling.

The Navigation library from the Android Jetpack suite facilitates work with fragments. The library contains a flaw that allows a malicious actor to launch any fragments in a navigation graph associated with an exported activity.

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Source Code Disclosure in ASP.NET apps

Recently, I came across an interesting ASP.NET application. It appeared to be secure, but it accidentally revealed its source code. Later, I found out that the used method is applicable to disclose code of many other .NET web applications.

Here are the details. If you just see an IIS or .NET app, this is for you.

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Bypassing browser tracking protection for CORS misconfiguration abuse

Cross-Origin Resource Sharing (CORS) is a web protocol that outlines how a web application on one domain can access resources from a server on a different domain. By default, web browsers have a Same-Origin Policy (SOP) that blocks these cross-origin requests for security purposes. However, CORS offers a secure way for servers to specify which origins are allowed to access their assets, thereby enabling a structured method of relaxing this policy.

In CORS, the server sends HTTP headers to instruct the browser on rules for making cross-origin requests. These rules define whether a particular HTTP request (such as GET or POST) from a certain origin is allowed. By managing the CORS headers, a server can control its resource accessibility on a case-by-case basis. This maintains the flexibility of cross-origin sharing without compromising overall security.

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Python ❤️ SSPI: Teaching Impacket to Respect Windows SSO

One handy feature of our private Impacket (by @fortra) fork is that it can leverage native SSPI interaction for authentication purposes when operating from a legit domain context on a Windows machine.

As far as the partial implementation of Ntsecapi represents a minified version of Oliver Lyak’s (@ly4k_) sspi module used in his great Certipy project, I’d like to break down its core features and showcase how easily it can be integrated into known Python tooling.

Given the Bring Your Own Interpreter (BYOI) concept, the combination of Impacket usage and SSPI capabilities can allow attackers to fly under the radar of endpoint security mechanisms as well as custom network detection rules more easily. We will discuss this in more detail further in the article.

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Binance Smart Chain Token Bridge Hack


On October 6th 2022, the BSC Token Hub bridge (hereinafter BSC), belonging to the largest cryptocurrency exchange, Binance, was hacked. This was one of the largest cryptocurrency hacks ever. BSC ensures the interaction between the Binance Beacon Chain blockchain used by Binance for decentralized management (stacking, voting) and Binance Smart Chain, an EVM-compatible blockchain used to create various decentralized applications. Hackers withdrew 2 million BNB (Binance’s cryptocurrency) from the bridge protocol, with 1 BNB worth $293 at the time. A total of $586 million was stolen.

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Jetty Features for Hacking Web Apps

To properly assess the security of a web application, it’s important to analyze it with regard to the server it will run on. Many things depend on the server, from processing user requests to the easiest way of achieving RCE. Armed with knowledge about the server, we can identify vulnerabilities in an application and make it more secure.

In this article we’ll look at Jetty, a well-known web server and Java web container that is typically deployed behind an Apache or NGINX proxy server. Here’s what we’ll cover:

  • How to find paths to all web applications on the server.
  • How to achieve RCE using an XML file.
  • How to bypass a web application firewall and remain unnoticed.
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Fork Bomb for Flutter

Flutter applications can be found in security analysis projects or bugbounty programs. Most often, such assets are simply overlooked due to the lack of methodologies and ways to reverse engineer them. I decided not to skip this anymore and developed the reFlutter tool. This article describes the results of my research.

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