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INTEL-SA-00117: Intel SGX Elevation of Privilege

Intel® SGX SDK Edger8r and Intel® Software Guard Extensions Platform Software Component
Intel ID: INTEL-SA-00117
Product family: Intel® SGX
Impact of vulnerability: Elevation of Privilege
Severity rating: Important
Original release: Mar 19, 2018

[…]CVE-2018-3626: The Edger8r tool in the Intel® Software Guard Extensions (SGX) Software Development Kit (SDK) before version 2.1.2 (Linux) and 1.9.6 (Windows) may generate code that is susceptible to a side channel attack, potentially allowing a local user to access unauthorized information. CVE-2018-5736: An elevation of privilege in Intel® Software Guard Extensions Platform Software Component before 1.9.105.42329 allows a local attacker to execute arbitrary code as administrator. CVE-2018-3626: Recently it was reported that the Edger8r Tool, a software component of the Intel® Software Guard Extensions (SGX) Software Development Kit (SDK), may generate C source code potentially leading to a software based side-channel vulnerability. […]Intel would like to thank Jo Van Bulck, Frank Piessens, and Raoul Strackx of Ku Leuven University for reporting CVE-2018-3626 and working with us on coordinated disclosure.

https://security-center.intel.com/advisory.aspx?intelid=INTEL-SA-00117&languageid=en-fr

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SgxPectre Attacks: Leaking Enclave Secrets via Speculative Execution

SgxPectre Attacks: Leaking Enclave Secrets via Speculative Execution
Guoxing Chen, Sanchuan Chen, Yuan Xiao, Yinqian Zhang, Zhiqiang Lin, Ten H. Lai
(Submitted on 25 Feb 2018)

This paper presents SgxPectre Attacks that exploit the recently disclosed CPU bugs to subvert the confidentiality of SGX enclaves. Particularly, we show that when branch prediction of the enclave code can be influenced by programs outside the enclave, the control flow of the enclave program can be temporarily altered to execute instructions that lead to observable cache-state changes. An adversary observing such changes can learn secrets inside the enclave memory or its internal registers, thus completely defeating the confidentiality guarantee offered by SGX. To demonstrate the practicality of our SgxPectre Attacks, we have systematically explored the possible attack vectors of branch target injection, approaches to win the race condition during enclave’s speculative execution, and techniques to automatically search for code patterns required for launching the attacks. Our study suggests that any enclave program could be vulnerable to SgxPectre Attacks since the desired code patterns are available in most SGX runtimes (e.g., Intel SGX SDK, Rust-SGX, and Graphene-SGX).

https://arxiv.org/abs/1802.09085

 

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SGX After Spectre and Meltdown: Status, Analysis and Remediations

SGX After Spectre and Meltdown: Status, Analysis and Remediations
Posted on January 25, 2018 by idfusionllc

Much has been written about the recently disclosed micro-architectural cache probing attacks named in the title of this document. These attacks, while known as a possibility for some time, have created significant concerns and remediation activity in the industry, secondary to the significant confidentiality threats they pose. These attacks are particularly problematic since they evade long standing protections that the industry has used as foundational constructs in the security design of modern operating systems.

While the threats to operating system protections have undergone significant discussion, there has been little official information surrounding the impact of this new threat class to Intel’s Software Guard eXtension (SGX) technology. This document is intended to provide support for system security architects and software engineers with respect to the impact of this new class of attack on SGX security guarantees. The development of this document was inspired by dialogue on the Intel SGX developer’s forum surrounding whether or not enclaves provide credible security guarantees in the face of these new threats.

Hardware and microcode enhancements introduced in the Intel Skylake micro-architecture provide the framework for the SGX Trusted Execution Environment (TEE). The SGX security architecture uses the notion of an enclave, which is an area of memory which contains data and code which can only be referenced by the enclave itself. Unauthorized access to these protected memory regions are blocked regardless of the privilege level of the context of execution attempting the access. As a result the premise is that enclaves will provide confidentiality and integrity guarantees even if the hardware, BIOS, hypervisor or operating system are compromised.[…]

https://software.intel.com/en-us/forums/intel-software-guard-extensions-intel-sgx/topic/754168

SGX After Spectre and Meltdown: Status, Analysis and Remediations

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Aurora: Providing Trusted System Services for Enclaves On an Untrusted System

Aurora: Providing Trusted System Services for Enclaves On an Untrusted System
Hongliang Liang, Mingyu Li, Qiong Zhang, Yue Yu, Lin Jiang, Yixiu Chen
(Submitted on 10 Feb 2018)

Intel SGX provisions shielded executions for security-sensitive computation, but lacks support for trusted system services (TSS), such as clock, network and filesystem. This makes \textit{enclaves} vulnerable to Iago attacks~\cite{DBLP:conf/asplos/CheckowayS13} in the face of a powerful malicious system. To mitigate this problem, we present Aurora, a novel architecture that provides TSSes via a secure channel between enclaves and devices on top of an untrusted system, and implement two types of TSSes, i.e. clock and end-to-end network. We evaluate our solution by porting SQLite and OpenSSL into Aurora, experimental results show that SQLite benefits from a \textit{microsecond} accuracy trusted clock and OpenSSL gains end-to-end secure network with about 1ms overhead.

https://arxiv.org/abs/1802.03530

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Upcoming Intel SGX Features Explained: Improved Virtualization, Configuration Management, and Key Sharing

Upcoming Intel® SGX Features Explained: Improved Virtualization, Configuration Management, and Key Sharing
Jethro Beekman
February 22nd, 2018
In an update to the Intel Software Developer’s Manual (SDM), Intel detailed upcoming changes to the Intel® SGX instruction set. The new features improve Enclave Page Cache management in virtualized environments and allow the addition of additional information to sealing key derivation and attestation reports. The improvements allow for better multi-tenancy with EPC oversubscription and easier configuration and software update management. I will go into detail on each of these in this post.[…]

https://www.fortanix.com/blog/2018/02/upcoming-intel-sgx-features-explained/

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EnclaveDB: A Secure Database using SGX

https://www.computer.org/csdl/proceedings/sp/2018/4353/00/index.html

EnclaveDB: A Secure Database using SGX
Christian Priebe , Imperial College London
Kapil Vaswani , Microsoft Research
Manuel Costa , Microsoft Research
We propose EnclaveDB, a database engine that guarantees confidentiality, integrity, and freshness for data and queries. EnclaveDB guarantees these properties even when the database administrator is malicious, when an attacker has compromised the operating system or the hypervisor, and when the database runs in an untrusted host in the cloud. EnclaveDB achieves this by placing sensitive data (tables, indexes and other metadata) in enclaves protected by trusted hardware (such as Intel SGX). EnclaveDB has a small trusted computing base, which includes an in-memory storage and query engine, a transaction manager and pre-compiled stored procedures. A key component of EnclaveDB is an efficient protocol for checking integrity and freshness of the database log. The protocol supports concurrent, asynchronous appends and truncation, and requires minimal synchronization between threads. Our experiments using standard database benchmarks and a performance model that simulates large enclaves show that EnclaveDB achieves strong security with low overhead (up to 40% for TPC-C) compared to an industry strength in-memory database engine.

https://www.computer.org/csdl/proceedings/sp/2018/4353/00/435301a405-abs.html

https://www.microsoft.com/en-us/research/publication/enclavedb-a-secure-database-using-sgx/

https://www.microsoft.com/en-us/research/uploads/prod/2018/02/enclavedb.pdf

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