Conference:  Defcon 31

Authors: Sven Cattell Founder nbhd.ai & AI Village, Rumman Chowdhury Founder Humane Intelligence, Austin Carson Founder SeedAI

2023-08-01

We’re running the largest live AI hacking event ever in the AI village this year. Anthropic, Google, HuggingFace, Meta, NVIDIA, OpenAI, and Stability, have all provided models to attack and Scale AI have built the platform. This event is orders of magnitude bigger than any previous AI red team effort. There are observers from the White House, NIST, NSF, and the EU coming to learn from hackers. We built this event to grow the community that knows how to effectively evaluate Large Language Models as it is much more than prompt injections and jailbreaks. AI works fundamentally differently to traditional software and only forms a part of a product. Trust and Security of AI in a system thus has to work fundamentally differently to traditional software. This is especially true for generative AI systems. The core difference is AI is a stochastic component of software and is allowed to make a small amount of mistakes. This changes bug hunting, reporting, and payouts. Come to this talk to hear about how and why we organized this, and the history of algorithmic & bias bounties that led up to the largest one ever at DEF CON 31. We’ll also give you some tips to help you in the contest.

Conference:  Defcon 31

Authors: Dan "AltF4" Petro Senior Security Engineer, Bishop Fox, David Vargas Senior Security Consultant, Bishop Fox

2023-08-01

Breaking into secure facilities used to be possible by inserting a listening device (such as an ESPKey) behind an RFID card reader and sniffing the unencrypted Wiegand badge numbers over the wire as they go to the backend controller. The physical security industry has taken notice and there's a new sheriff in town: The encrypted protocol OSDP which is starting to be rolled into production. Surely encryption will solve our problems and prevent MitM attacks right? ... right? In this presentation, we'll demonstrate over a dozen vulnerabilities, concerning problems, and general "WTF"s in the OSDP protocol that let it be subverted, coerced, and totally bypassed. This ranges from deeply in-the-weeds clever cryptographic attacks, to boneheaded mistakes that undermine the whole thing. We will also demonstrate a practical pentesting tool that can be inserted behind an RFID badge reader to exploit these vulnerabilities. Get your orange vest and carry a ladder, because we're going onsite!

Conference:  Defcon 31

Authors: Thomas Chauchefoin Vulnerability Researcher @ Sonar, Paul Gerste Vulnerability Researcher @ Sonar

2023-08-01

Developers are threat actors' targets of choice because of their access to business-critical services. After compromising a single developer, they could push code changes or obtain sensitive information. For instance, a recent campaign attributed to North Korea set up social network profiles to social engineer and infect prominent figures of the developer community with malicious Visual Studio projects and browser exploits. At the same time, modern development tools offer increasingly advanced features and deep integration with ecosystems, sometimes at the cost of basic security measures. Code editors tried to counterbalance it by introducing new lines of defense (e.g., "Workspace Trust"), leading to a cat-and-mouse game to restrict access while keeping most features available by default. In this talk, we present the state of the art of Visual Studio Code's security. We go in-depth into its attack surface, how its extensions work, and the technical details of two vulnerabilities we found in Visual Studio Code. These findings, CVE-2021-43891 and CVE-2022-30129, led to a $30.000 bounty with an unexpected twist. We also present 1-days discovered by other researchers to develop the audience's intuition. These concepts apply to most IDEs of the market so everybody will now think twice before opening third-party code!

Conference:  Defcon 31

Authors: Austin Emmitt Senior Security Researcher at Trellix Advanced Research Center

2023-08-01

In 2021 the FORCEDENTRY sandbox escape introduced the usage of NSPredicate in an iOS exploit. This new technique allowed attackers to sidestep codesigning, ASLR, and all other mitigations to execute arbitrary code on Apple devices. As a result, Apple put in place new restrictions to make NSPredicate less powerful and less useful for exploits. This presentation will cover new research showing that these added restrictions could be completely circumvented in iOS 16, and how NSPredicates could be exploited to gain code execution in many privileged iOS processes. This technical deep dive will be a rare instance of iOS security that anyone can comprehend without years of experience. After an overview of the classes involved, we will explore the full syntax of NSPredicate and cover how it can be used to script the Objective-C runtime and even call any C function. It will be shown that PAC can still be bypassed 100% reliably with NSPredicates in order to execute any function with arbitrary arguments. A new tool will be unveiled to help craft complex NSPredicates to execute arbitrary code and inject those predicates in any application. Additionally, a demonstration will be given which executes arbitrary code in the highly privileged Preferences app. Finally, the talk will cover a bypass of NSPredicateVisitor implementations which allows a malicious process to evaluate any NSPredicate within several system processes including coreduetd, appstored, OSLogService, and SpringBoard. Next there will be a live demo of exploiting SpringBoard to steal a user’s notifications and location data. The presentation will end with some discussion about what can still be done with NSPredicates now that these issues have been fixed, including bypassing App Store Review, and what app developers should know to keep their own apps safe.

Conference:  Defcon 31

Authors: good_pseudonym

2023-08-01

PBX (Private Branch Exchange) and UC (Unified Communications) servers are the big communication brokers in enterprise environments where they love on-prem. They do everything to enable internal and external communications including voice, video, conferencing and messaging. But a broader scope also means a broader attack surface. In this talk, we'll give an overview PBX/UC systems, what kind of attack surface they have, as well as several bugs that we recently found in two popular PBX/UC products. The journey includes deep-diving Java's Runtime.exec(), decrypting encrypted PHP, bypassing license restrictions, pretending to be a phone, and (of course) getting some shells.

Conference:  Defcon 31

Authors: Cooper Quintin Senior Staff Technologist – EFF

2023-08-01

For the last 6 years my colleagues and I have been tracking the activities of the cyber-mercenaries we call Dark Caracal. In this time we have observed them make a number of hilarious mistakes which have allowed us to gain crucial insights into their activities and victims. In this talk we will discuss the story of Dark Caracal, the mistakes they have made, and how they have managed to remain effective despite quite possibly being the dumbest APT to ever exist.

Conference:  Defcon 31

Authors: Michael Stepankin Security Researcher at GitHub

2023-08-01

Although x509 certificates have been here for a while, they have become more popular for client authentication in zero-trust networks in recent years. Mutual TLS, or authentication based on X509 certificates in general, brings advantages compared to passwords or tokens, but you get increased complexity in return. In this talk, we’ll deep dive into some novel attacks on mTLS authentication. We won’t bother you with heavy crypto stuff, but instead we’ll have a look at implementation vulnerabilities and how developers can make their mTLS systems vulnerable to user impersonation, privilege escalation and information leakages. We present some CVEs we found in popular open-source identity servers and ways to exploit them. Finally, we’ll explain how these vulnerabilities can be spotted in source code and how the safe code looks like.

Conference:  Defcon 31

Authors: Jonathan Birch Principal Security Software Engineer, Microsoft

2023-08-01

Exploits of insecure serialization leading to remote code execution have been a common attack against .NET applications for some time. But it's generally assumed that exploiting serialization requires that an application directly uses a serializer and that it unsafely reads data that an attacker can tamper with. This talk demonstrates attacks that violate both of these assumptions. This includes serialization exploits of platforms that don't use well-known .NET serializers and methods to exploit deserialization even when the serialized data cannot be tampered with. Remote code execution vulnerabilities in MongoDB, LiteDB, ServiceStack.Redis, RavenDB, MartenDB, JSON.Net and the .NET JavaScriptSerializer are all demonstrated. Techniques to both scan for and mitigate these vulnerabilities are also discussed, along with methods and obstacles for exploiting serialization in .NET 6+.

Conference:  Defcon 31

Authors: Laurie Kirk Security Researcher at Microsoft

2023-08-01

Android malware creators constantly struggle to devise innovative methods to obscure apps and impede reverse engineering. As numerous standard techniques have lost efficacy, I'll unveil the next frontier in Android obfuscation: runtime manipulation. Runtime manipulation alters standard application flow-of-control to bypass decompilers and emulators. In this talk, I'll reveal my strategy for pinpointing manipulation targets in Android's source code. I will describe how I craft manipulators in native C++ once a suitable target has been located. This is accomplished by hooking Java methods via the Java Native Interface (JNI) and typecasting the handle to a C-style pointer. Runtime manipulation can entirely remove traces of ClassLoader calls which are unavoidable for standard Dalvik Executable (DEX) packing, but are also easily discovered and hooked. This technique also effectively breaks cross-reference calculations within all Android decompilers. I will demonstrate and equip attendees with a custom Android library for devices running Android 13, providing a new tool that enables runtime manipulation experimentation. In addition, I'll demonstrate my methodology for pinpointing Java targets and modifying their underlying native data structures.

Conference:  Defcon 31

Authors: Joe Sullivan CEO of Ukraine Friends

2023-08-01

The federal criminal case of United States v. Joseph Sullivan, NDCA 3-20-CR-337 WHO, has been covered and debated quite publicly since I was fired by the new Uber CEO in November 2017, a year after the incident. Most discussion has focused on questions of my guilt or innocence, the culpability of other executives at the company, and the implications of the case for other security executives. Less has been written about the guilt or innocence of those who accessed Uber’s AWS environment in October 2016 and triggered an incident response by emailing me and asking for payment. After we met them, my team and I did not consider those 19- and 20-year-old kids to be criminal actors and treated them as security researchers. Yet both also faced federal criminal charges. During my talk I will review the extraordinary investigation done by my team at Uber and put it into the context of other historical cases we and I had worked on. Whether or not you consider them to be security researchers, there are many lessons to be learned related to the dynamics between researchers and companies and the dynamics between companies and the government.