News
Next Seminar on 24.04.2024
Written on 21.04.2024 18:49 by Mang Zhao
Dear All,
The next seminar(s) take place on 24.04.2024 at 14:00 (Session A) and 14:00 (Session B).
Session A: (14:00-15:30)
Jonas Büchner, Margarita Keteva, Oliver Schedler
https://cispa-de.zoom.us/j/96786205841?pwd=M3FOQ3dSczRabDNLb3F1czVXVUpvdz09
Meeting-ID: 967 8620 5841
Kenncode: BT!u5=
Session B: (14:00-15:30)
Sven Kuppe, Andreas Knobel, Tristan Hornetz
https://cispa-de.zoom-x.de/j/66136901453?pwd=YVBSZU9peUpvUlk4bWp3MDR4cGlUUT09
Session A:
14:00 - 14:30
Speaker: Jonas Büchner
Type of talk: Master Final
Advisor: Dr. Michael Schwarz
Title: Reverse Engineering UEFI Firmware to Discover Hidden CPU Features
Research Area: RA4
Abstract:
With every new generation of x86 processors, their complexity of features increases. Luckily, CPU vendors allow the configuration of many of these CPU features. This is commonly done by using model-specific registers (MSRs). Besides configuration, these also allow performance monitoring and debugging. Naturally, a greater knowledge of the available MSRs improves control over the processor for researchers and users. While a lot of the MSRs are documented by Intel and AMD, there still remains a plethora of undocumented MSRs.
MSRs can only be accessed with the privileged RDMSR and WRMSR instructions. Therefore, the usage of MSRs is largely limited to low-level code, firmware in particular. The Unified Extensible Firmware Interface (UEFI) is a specification for firmware, which is implemented in many modern x86 systems. Because of its function, it is expected to make heavy use of MSRs and is therefore a primary target for research.
In this thesis, we explore methods to automatically discover the MSRs used in UEFI firmware. We use static analysis, which analyzes the firmware based on the machine code itself. We also use dynamic analysis to observe the execution of firmware binaries, working with both concrete and symbolic domains. We find a total of 233 different MSRs across 8 analyzed firmware images. 51 of these MSRs are not documented in the Intel SDM or AMD manual. We evaluate our methods and analyze the found MSRs, coming to the conclusion that reverse-engineering can find many, also undocumented, MSRs in firmware. Furthermore, it can help in finding the functionality of undocumented MSRs.
14:30 - 15:00
Speaker: Margarita Keteva
Type of talk: Bachelor Intro
Advisor: Lucjan Hanzlik
Title: Evaluating FIDO2 Attestations in Real-World and Security Keys Counter Behaviour
Research Area: RA1
Abstract:
FIDO2 introduces standards for secure passwordless authentication over the Internet. It consists of two protocols, namely CTAP2 (Client to Authenticator Protocol) and WebAuthn (W3C Web Authentication). Attestation and assertion are two terms that refer to the security key's registration and authentication.
In this study, we will analyse and evaluate the usage of FIDO2 in the real world by targeting the most visited websites and the attestations returned by security keys during the registration phase. The collected payloads from different authenticators will provide a broader scope of data.
Each аttestation and аssertion contains a counter that indicates the number of operations performed and signed by the authenticator. It is a measurement against cloning attacks. By evaluating the values of multiple responses and examining the change of the counter, we can calculate the probability of detecting the attack after its execution.
15:00 - 15:30
Speaker: Oliver Schedler
No information is provided.
Session B:
14:00 - 14:30
Speaker: Sven Kuppe
Type of talk: Bachelor Final
Advisor: Lucjan Hanzlik
Title: Blockchain-Based Verification of Android Keystore-Generated Key Attestations using Smart Contracts
Research Area: RA1
Abstract:
When using cryptocurrencies, it is important to ensure the security of our transactions. Therefore, we must ask ourselves how we can be certain that our recipient has reliable key management and securely stores their private key. This project aims to address these safety concerns by utilizing Android's hardware-backed keystore feature, available in modern smartphones. We create a smart contract that serves as a trust mechanism. It verifies the presence of a hardware-backed key in a device and stores the outcome on the blockchain. The goal of this work is to develop an Android application and a specialised smart contract. The application creates a key within its secure memory and provides a proof that the key is inside its secure memory. This proof consists of a certificate chain. The smart contract reads the certificates in the chain and verifies each one. If the certificate chain is valid, the successful outcome is stored on the blockchain. This establishes trust in the receiver's devices without requiring additional verification methods and provides an answer to the security questions mentioned above.
14:30 - 15:00
Speaker: Andreas Knobel
No information is provided.
15:00 - 15:30
Speaker: Tristan Hornetz
Type of talk: Master Final
Advisor: Dr. Michael Schwarz, Lukas Gerlach
Title: Execute-Only Memory as a Security Hardening Feature on x86-64
Research Area: RA3
Abstract:
Execute-Only Memory (XOM) is a rarely used, but versatile memory protection scheme, in which instruction fetches are permitted, but data reads and writes are not. In the context of x86_64, it is mainly used in defensive schemes against code-reuse attacks. Besides this however, there is very little research on applications that could benefit from its unique memory protection capabilities. In my master’s thesis, I therefore investigate the characteristics of XOM, with the primary goal of identifying novel application scenarios. To this end, I present a set of software libraries that make XOM available to user-mode programs and use them to conduct studies on XOM’s performance aspects and potential attack vectors.
The results of this effort are two key observations: Firstly, XOM proves to be highly resistant against transient execution attacks like Spectre and Meltdown. XOM can thus serve as a component of low-cost mitigation schemes against them. Secondly, it is possible to use XOM to hide cryptographic secrets from privileged local attackers. This may provide an alternative to Trusted Execution Environments on platforms where such facilities do not exist, with potential applications in Digital Rights Management.