Pub Date : 2020-05-01DOI: 10.1109/SP40000.2020.00056
James Pavur, Daniel Moser, Martin Strohmeier, Vincent Lenders, I. Martinovic
Very Small Aperture Terminals (VSAT) have revolutionized maritime operations. However, the security dimensions of maritime VSAT services are not well understood. Historically, high equipment costs have acted as a barrier to entry for both researchers and attackers. In this paper we demonstrate a substantial change in threat model, proving practical attacks against maritime VSAT networks with less than $400 of widely-available television equipment. This is achieved through GSExtract, a purpose-built forensic tool which enables the extraction of IP traffic from highly corrupted VSAT data streams.The implications of this threat are assessed experimentally through the analysis of more than 1.3 TB of real-world maritime VSAT recordings encompassing 26 million square kilometers of coverage area. The underlying network platform employed in these systems is representative of more than 60% of the global maritime VSAT services market. We find that sensitive data belonging to some of the world's largest maritime companies is regularly leaked over VSAT ship-to-shore communications. This threat is contextualized through illustrative case studies ranging from the interception and alteration of navigational charts to theft of passport and credit card details. Beyond this, we demonstrate the ability to arbitrarily intercept and modify TCP sessions under certain network configurations, enabling man-in-the-middle and denial of service attacks against ships at sea. The paper concludes with a brief discussion of the unique requirements and challenges for encryption in VSAT environments.
{"title":"A Tale of Sea and Sky On the Security of Maritime VSAT Communications","authors":"James Pavur, Daniel Moser, Martin Strohmeier, Vincent Lenders, I. Martinovic","doi":"10.1109/SP40000.2020.00056","DOIUrl":"https://doi.org/10.1109/SP40000.2020.00056","url":null,"abstract":"Very Small Aperture Terminals (VSAT) have revolutionized maritime operations. However, the security dimensions of maritime VSAT services are not well understood. Historically, high equipment costs have acted as a barrier to entry for both researchers and attackers. In this paper we demonstrate a substantial change in threat model, proving practical attacks against maritime VSAT networks with less than $400 of widely-available television equipment. This is achieved through GSExtract, a purpose-built forensic tool which enables the extraction of IP traffic from highly corrupted VSAT data streams.The implications of this threat are assessed experimentally through the analysis of more than 1.3 TB of real-world maritime VSAT recordings encompassing 26 million square kilometers of coverage area. The underlying network platform employed in these systems is representative of more than 60% of the global maritime VSAT services market. We find that sensitive data belonging to some of the world's largest maritime companies is regularly leaked over VSAT ship-to-shore communications. This threat is contextualized through illustrative case studies ranging from the interception and alteration of navigational charts to theft of passport and credit card details. Beyond this, we demonstrate the ability to arbitrarily intercept and modify TCP sessions under certain network configurations, enabling man-in-the-middle and denial of service attacks against ships at sea. The paper concludes with a brief discussion of the unique requirements and challenges for encryption in VSAT environments.","PeriodicalId":6849,"journal":{"name":"2020 IEEE Symposium on Security and Privacy (SP)","volume":"54 1","pages":"1384-1400"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81334339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1109/SP40000.2020.00007
Tegan Brennan, Nicolás Rosner, T. Bultan
Side-channel vulnerabilities in software are caused by an observable imbalance in resource usage across different program paths. We show that just-in-time (JIT) compilation, which is crucial to the runtime performance of modern interpreted languages, can introduce timing side channels in cases where the input distribution to the program is non-uniform. Such timing channels can enable an attacker to infer potentially sensitive information about predicates on the program input.We define three attack models under which such side channels are harnessable and five vulnerability templates to detect susceptible code fragments and predicates. We also propose profiling algorithms to generate the representative statistical information necessary for the attacker to perform accurate inference.We systematically evaluate the strength of these JIT-based side channels on the java.lang.String, java.lang.Math, and java.math.BigInteger classes from the Java standard library, and on the JavaScript built-in objects String, Math, and Array. We carry out our evaluation using two widely adopted, open-source, JIT-enhanced runtime engines for the Java and JavaScript languages: the Oracle HotSpot Java Virtual Machine and the Google V8 JavaScript engine, respectively.Finally, we demonstrate a few examples of JIT-based side channels in the Apache Shiro security framework and the GraphHopper route planning server, and show that they are observable over the public Internet.
{"title":"JIT Leaks: Inducing Timing Side Channels through Just-In-Time Compilation","authors":"Tegan Brennan, Nicolás Rosner, T. Bultan","doi":"10.1109/SP40000.2020.00007","DOIUrl":"https://doi.org/10.1109/SP40000.2020.00007","url":null,"abstract":"Side-channel vulnerabilities in software are caused by an observable imbalance in resource usage across different program paths. We show that just-in-time (JIT) compilation, which is crucial to the runtime performance of modern interpreted languages, can introduce timing side channels in cases where the input distribution to the program is non-uniform. Such timing channels can enable an attacker to infer potentially sensitive information about predicates on the program input.We define three attack models under which such side channels are harnessable and five vulnerability templates to detect susceptible code fragments and predicates. We also propose profiling algorithms to generate the representative statistical information necessary for the attacker to perform accurate inference.We systematically evaluate the strength of these JIT-based side channels on the java.lang.String, java.lang.Math, and java.math.BigInteger classes from the Java standard library, and on the JavaScript built-in objects String, Math, and Array. We carry out our evaluation using two widely adopted, open-source, JIT-enhanced runtime engines for the Java and JavaScript languages: the Oracle HotSpot Java Virtual Machine and the Google V8 JavaScript engine, respectively.Finally, we demonstrate a few examples of JIT-based side channels in the Apache Shiro security framework and the GraphHopper route planning server, and show that they are observable over the public Internet.","PeriodicalId":6849,"journal":{"name":"2020 IEEE Symposium on Security and Privacy (SP)","volume":"29 1","pages":"1207-1222"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87331063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1109/SP40000.2020.00020
Andrew Kwong, Daniel Genkin, D. Gruss, Y. Yarom
The Rowhammer bug is a reliability issue in DRAM cells that can enable an unprivileged adversary to flip the values of bits in neighboring rows on the memory module. Previous work has exploited this for various types of fault attacks across security boundaries, where the attacker flips inaccessible bits, often resulting in privilege escalation. It is widely assumed however, that bit flips within the adversary’s own private memory have no security implications, as the attacker can already modify its private memory via regular write operations.We demonstrate that this assumption is incorrect, by employing Rowhammer as a read side channel. More specifically, we show how an unprivileged attacker can exploit the data dependence between Rowhammer induced bit flips and the bits in nearby rows to deduce these bits, including values belonging to other processes and the kernel. Thus, the primary contribution of this work is to show that Rowhammer is a threat to not only integrity, but to confidentiality as well.Furthermore, in contrast to Rowhammer write side channels, which require persistent bit flips, our read channel succeeds even when ECC memory detects and corrects every bit flip. Thus, we demonstrate the first security implication of successfully-corrected bit flips, which were previously considered benign.To demonstrate the implications of this read side channel, we present an end-to-end attack on OpenSSH 7.9 that extracts an RSA-2048 key from the root level SSH daemon. To accomplish this, we develop novel techniques for massaging memory from user space into an exploitable state, and use the DRAM rowbuffer timing side channel to locate physically contiguous memory necessary for double-sided Rowhammering. Unlike previous Rowhammer attacks, our attack does not require the use of huge pages, and it works on Ubuntu Linux under its default configuration settings.
{"title":"RAMBleed: Reading Bits in Memory Without Accessing Them","authors":"Andrew Kwong, Daniel Genkin, D. Gruss, Y. Yarom","doi":"10.1109/SP40000.2020.00020","DOIUrl":"https://doi.org/10.1109/SP40000.2020.00020","url":null,"abstract":"The Rowhammer bug is a reliability issue in DRAM cells that can enable an unprivileged adversary to flip the values of bits in neighboring rows on the memory module. Previous work has exploited this for various types of fault attacks across security boundaries, where the attacker flips inaccessible bits, often resulting in privilege escalation. It is widely assumed however, that bit flips within the adversary’s own private memory have no security implications, as the attacker can already modify its private memory via regular write operations.We demonstrate that this assumption is incorrect, by employing Rowhammer as a read side channel. More specifically, we show how an unprivileged attacker can exploit the data dependence between Rowhammer induced bit flips and the bits in nearby rows to deduce these bits, including values belonging to other processes and the kernel. Thus, the primary contribution of this work is to show that Rowhammer is a threat to not only integrity, but to confidentiality as well.Furthermore, in contrast to Rowhammer write side channels, which require persistent bit flips, our read channel succeeds even when ECC memory detects and corrects every bit flip. Thus, we demonstrate the first security implication of successfully-corrected bit flips, which were previously considered benign.To demonstrate the implications of this read side channel, we present an end-to-end attack on OpenSSH 7.9 that extracts an RSA-2048 key from the root level SSH daemon. To accomplish this, we develop novel techniques for massaging memory from user space into an exploitable state, and use the DRAM rowbuffer timing side channel to locate physically contiguous memory necessary for double-sided Rowhammering. Unlike previous Rowhammer attacks, our attack does not require the use of huge pages, and it works on Ubuntu Linux under its default configuration settings.","PeriodicalId":6849,"journal":{"name":"2020 IEEE Symposium on Security and Privacy (SP)","volume":"56 1","pages":"695-711"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85716389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Malware is a prominent security threat and exposing malware behavior is a critical challenge. Recent malware often has payload that is only released when certain conditions are satisfied. It is hence difficult to fully disclose the payload by simply executing the malware. In addition, malware samples may be equipped with cloaking techniques such as VM detectors that stop execution once detecting that the malware is being monitored. Forced execution is a highly effective method to penetrate malware self-protection and expose hidden behavior, by forcefully setting certain branch outcomes. However, an existing state-of-the-art forced execution technique X-Force is very heavyweight, requiring tracing individual instructions, reasoning about pointer alias relations on-the-fly, and repairing invalid pointers by on-demand memory allocation. We develop a light-weight and practical forced execution technique. Without losing analysis precision, it avoids tracking individual instructions and on-demand allocation. Under our scheme, a forced execution is very similar to a native one. It features a novel memory pre-planning phase that pre-allocates a large memory buffer, and then initializes the buffer, and variables in the subject binary, with carefully crafted values in a random fashion before the real execution. The pre-planning is designed in such a way that dereferencing an invalid pointer has a very large chance to fall into the pre-allocated region and hence does not cause any exception, and semantically unrelated invalid pointer dereferences highly likely access disjoint (pre-allocated) memory regions, avoiding state corruptions with probabilistic guarantees. Our experiments show that our technique is 84 times faster than X-Force, has 6.5X and 10% fewer false positives and negatives for program dependence detection, respectively, and can expose 98% more malicious behaviors in 400 recent malware samples.
{"title":"PMP: Cost-effective Forced Execution with Probabilistic Memory Pre-planning","authors":"Wei You, Zhuo Zhang, Yonghwi Kwon, Yousra Aafer, Fei Peng, Yu Shi, C. Harmon, X. Zhang","doi":"10.1109/SP40000.2020.00035","DOIUrl":"https://doi.org/10.1109/SP40000.2020.00035","url":null,"abstract":"Malware is a prominent security threat and exposing malware behavior is a critical challenge. Recent malware often has payload that is only released when certain conditions are satisfied. It is hence difficult to fully disclose the payload by simply executing the malware. In addition, malware samples may be equipped with cloaking techniques such as VM detectors that stop execution once detecting that the malware is being monitored. Forced execution is a highly effective method to penetrate malware self-protection and expose hidden behavior, by forcefully setting certain branch outcomes. However, an existing state-of-the-art forced execution technique X-Force is very heavyweight, requiring tracing individual instructions, reasoning about pointer alias relations on-the-fly, and repairing invalid pointers by on-demand memory allocation. We develop a light-weight and practical forced execution technique. Without losing analysis precision, it avoids tracking individual instructions and on-demand allocation. Under our scheme, a forced execution is very similar to a native one. It features a novel memory pre-planning phase that pre-allocates a large memory buffer, and then initializes the buffer, and variables in the subject binary, with carefully crafted values in a random fashion before the real execution. The pre-planning is designed in such a way that dereferencing an invalid pointer has a very large chance to fall into the pre-allocated region and hence does not cause any exception, and semantically unrelated invalid pointer dereferences highly likely access disjoint (pre-allocated) memory regions, avoiding state corruptions with probabilistic guarantees. Our experiments show that our technique is 84 times faster than X-Force, has 6.5X and 10% fewer false positives and negatives for program dependence detection, respectively, and can expose 98% more malicious behaviors in 400 recent malware samples.","PeriodicalId":6849,"journal":{"name":"2020 IEEE Symposium on Security and Privacy (SP)","volume":"25 1","pages":"1121-1138"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78245346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1109/SP40000.2020.00037
E. Shi
We propose Path Oblivious Heap, an extremely simple, practical, and optimal oblivious priority queue. Our construction also implies a practical and optimal oblivious sorting algorithm which we call Path Oblivious Sort. Not only are our algorithms asymptotically optimal, we show that their practical performance is only a small constant factor worse than insecure baselines. More specificially, assuming roughly logarithmic client private storage, Path Oblivious Heap consumes 2× to 7× more bandwidth than the ordinary insecure binary heap; and Path Oblivious Sort consumes 4.5× to 6× more bandwidth than the insecure Merge Sort. We show that these performance results improve existing works by 1-2 orders of magnitude. Finally, we evaluate our algorithm for a multi-party computation scenario and show 7x to 8x reduction in the number of symmetric encryptions relative to the state of the art1.
{"title":"Path Oblivious Heap: Optimal and Practical Oblivious Priority Queue","authors":"E. Shi","doi":"10.1109/SP40000.2020.00037","DOIUrl":"https://doi.org/10.1109/SP40000.2020.00037","url":null,"abstract":"We propose Path Oblivious Heap, an extremely simple, practical, and optimal oblivious priority queue. Our construction also implies a practical and optimal oblivious sorting algorithm which we call Path Oblivious Sort. Not only are our algorithms asymptotically optimal, we show that their practical performance is only a small constant factor worse than insecure baselines. More specificially, assuming roughly logarithmic client private storage, Path Oblivious Heap consumes 2× to 7× more bandwidth than the ordinary insecure binary heap; and Path Oblivious Sort consumes 4.5× to 6× more bandwidth than the insecure Merge Sort. We show that these performance results improve existing works by 1-2 orders of magnitude. Finally, we evaluate our algorithm for a multi-party computation scenario and show 7x to 8x reduction in the number of symmetric encryptions relative to the state of the art1.","PeriodicalId":6849,"journal":{"name":"2020 IEEE Symposium on Security and Privacy (SP)","volume":"304 1","pages":"842-858"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73750674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1109/SP40000.2020.00036
Nilo Redini, Aravind Machiry, Ruoyu Wang, Chad Spensky, Andrea Continella, Yan Shoshitaishvili, C. Kruegel, G. Vigna
Low-power, single-purpose embedded devices (e.g., routers and IoT devices) have become ubiquitous. While they automate and simplify many aspects of users’ lives, recent large-scale attacks have shown that their sheer number poses a severe threat to the Internet infrastructure. Unfortunately, the software on these systems is hardware-dependent, and typically executes in unique, minimal environments with non-standard configurations, making security analysis particularly challenging. Many of the existing devices implement their functionality through the use of multiple binaries. This multi-binary service implementation renders current static and dynamic analysis techniques either ineffective or inefficient, as they are unable to identify and adequately model the communication between the various executables. In this paper, we present Karonte, a static analysis approach capable of analyzing embedded-device firmware by modeling and tracking multi-binary interactions. Our approach propagates taint information between binaries to detect insecure interactions and identify vulnerabilities. We first evaluated Karonte on 53 firmware samples from various vendors, showing that our prototype tool can successfully track and constrain multi-binary interactions. This led to the discovery of 46 zero-day bugs. Then, we performed a large-scale experiment on 899 different samples, showing that Karonte scales well with firmware samples of different size and complexity.
{"title":"Karonte: Detecting Insecure Multi-binary Interactions in Embedded Firmware","authors":"Nilo Redini, Aravind Machiry, Ruoyu Wang, Chad Spensky, Andrea Continella, Yan Shoshitaishvili, C. Kruegel, G. Vigna","doi":"10.1109/SP40000.2020.00036","DOIUrl":"https://doi.org/10.1109/SP40000.2020.00036","url":null,"abstract":"Low-power, single-purpose embedded devices (e.g., routers and IoT devices) have become ubiquitous. While they automate and simplify many aspects of users’ lives, recent large-scale attacks have shown that their sheer number poses a severe threat to the Internet infrastructure. Unfortunately, the software on these systems is hardware-dependent, and typically executes in unique, minimal environments with non-standard configurations, making security analysis particularly challenging. Many of the existing devices implement their functionality through the use of multiple binaries. This multi-binary service implementation renders current static and dynamic analysis techniques either ineffective or inefficient, as they are unable to identify and adequately model the communication between the various executables. In this paper, we present Karonte, a static analysis approach capable of analyzing embedded-device firmware by modeling and tracking multi-binary interactions. Our approach propagates taint information between binaries to detect insecure interactions and identify vulnerabilities. We first evaluated Karonte on 53 firmware samples from various vendors, showing that our prototype tool can successfully track and constrain multi-binary interactions. This led to the discovery of 46 zero-day bugs. Then, we performed a large-scale experiment on 899 different samples, showing that Karonte scales well with firmware samples of different size and complexity.","PeriodicalId":6849,"journal":{"name":"2020 IEEE Symposium on Security and Privacy (SP)","volume":"191 1","pages":"1544-1561"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79772039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1109/SP40000.2020.00076
Célestin Matte, Nataliia Bielova, C. Santos
As a result of the GDPR and the ePrivacy Directive, European users encounter cookie banners on almost every website. Many of such banners are implemented by Consent Management Providers (CMPs), who respect IAB Europe’s Transparency and Consent Framework (TCF). Via cookie banners, CMPs collect and disseminate user consent to third parties. In this work, we systematically study IAB Europe’s TCF and analyze consent stored behind the user interface of TCF cookie banners. We analyze the GDPR and the ePrivacy Directive to identify potential legal violations in implementations of cookie banners based on the storage of consent and detect such suspected violations by crawling 1 426 websites that contains TCF banners, found among 28 257 crawled European websites. With two automatic and semi-automatic crawl campaigns, we detect suspected violations, and we find that: 141 websites register positive consent even if the user has not made their choice; 236 websites nudge the users towards accepting consent by pre-selecting options; and 27 websites store a positive consent even if the user has explicitly opted out. Performing extensive tests on 560 websites, we find at least one suspected violation in 54% of them. Finally, we provide a browser extension to facilitate manual detection of suspected violations for regular users and Data Protection Authorities.
{"title":"Do Cookie Banners Respect my Choice? : Measuring Legal Compliance of Banners from IAB Europe’s Transparency and Consent Framework","authors":"Célestin Matte, Nataliia Bielova, C. Santos","doi":"10.1109/SP40000.2020.00076","DOIUrl":"https://doi.org/10.1109/SP40000.2020.00076","url":null,"abstract":"As a result of the GDPR and the ePrivacy Directive, European users encounter cookie banners on almost every website. Many of such banners are implemented by Consent Management Providers (CMPs), who respect IAB Europe’s Transparency and Consent Framework (TCF). Via cookie banners, CMPs collect and disseminate user consent to third parties. In this work, we systematically study IAB Europe’s TCF and analyze consent stored behind the user interface of TCF cookie banners. We analyze the GDPR and the ePrivacy Directive to identify potential legal violations in implementations of cookie banners based on the storage of consent and detect such suspected violations by crawling 1 426 websites that contains TCF banners, found among 28 257 crawled European websites. With two automatic and semi-automatic crawl campaigns, we detect suspected violations, and we find that: 141 websites register positive consent even if the user has not made their choice; 236 websites nudge the users towards accepting consent by pre-selecting options; and 27 websites store a positive consent even if the user has explicitly opted out. Performing extensive tests on 560 websites, we find at least one suspected violation in 54% of them. Finally, we provide a browser extension to facilitate manual detection of suspected violations for regular users and Data Protection Authorities.","PeriodicalId":6849,"journal":{"name":"2020 IEEE Symposium on Security and Privacy (SP)","volume":"4 1","pages":"791-809"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85209853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1109/SP40000.2020.00089
Jo Van Bulck, D. Moghimi, Michael Schwarz, Moritz Lipp, Marina Minkin, Daniel Genkin, Y. Yarom, B. Sunar, D. Gruss, F. Piessens
The recent Spectre attack first showed how to inject incorrect branch targets into a victim domain by poisoning microarchitectural branch prediction history. In this paper, we generalize injection-based methodologies to the memory hierarchy by directly injecting incorrect, attacker-controlled values into a victim’s transient execution. We propose Load Value Injection (LVI) as an innovative technique to reversely exploit Meltdown-type microarchitectural data leakage. LVI abuses that faulting or assisted loads, executed by a legitimate victim program, may transiently use dummy values or poisoned data from various microarchitectural buffers, before eventually being re-issued by the processor. We show how LVI gadgets allow to expose victim secrets and hijack transient control flow. We practically demonstrate LVI in several proof-of-concept attacks against Intel SGX enclaves, and we discuss implications for traditional user process and kernel isolation. State-of-the-art Meltdown and Spectre defenses, including widespread silicon-level and microcode mitigations, are orthogonal to our novel LVI techniques. LVI drastically widens the spectrum of incorrect transient paths. Fully mitigating our attacks requires serializing the processor pipeline with lfence instructions after possibly every memory load. Additionally and even worse, due to implicit loads, certain instructions have to be blacklisted, including the ubiquitous x86 ret instruction. Intel plans compiler and assembler-based full mitigations that will allow at least SGX enclave programs to remain secure on LVI-vulnerable systems. Depending on the application and optimization strategy, we observe extensive overheads of factor 2 to 19 for prototype implementations of the full mitigation.
最近的Spectre攻击首次展示了如何通过毒害微架构分支预测历史将错误的分支目标注入受害者域。在本文中，我们通过将不正确的、攻击者控制的值直接注入受害者的瞬态执行，将基于注入的方法推广到内存层次。我们提出负载值注入(Load Value Injection, LVI)作为一种创新技术来反向利用熔毁型微架构数据泄漏。LVI滥用了由合法受害者程序执行的错误或辅助负载在最终由处理器重新发出之前，可能会暂时使用来自各种微体系结构缓冲区的虚拟值或中毒数据。我们展示了LVI小工具如何允许暴露受害者的秘密和劫持瞬态控制流。我们在针对Intel SGX飞地的几个概念验证攻击中实际演示了LVI，并讨论了对传统用户进程和内核隔离的影响。最先进的熔解和幽灵防御，包括广泛的硅级和微码缓解，与我们的新型LVI技术正交。LVI极大地拓宽了不正确瞬态路径的频谱。完全减轻我们的攻击需要在每次内存加载之后用lfence指令序列化处理器管道。此外，更糟糕的是，由于隐式加载，某些指令必须被列入黑名单，包括无处不在的x86 ret指令。英特尔计划基于编译器和汇编器的全面缓解措施，至少允许SGX飞地程序在易受lvi攻击的系统上保持安全。根据应用程序和优化策略的不同，我们观察到完整缓解的原型实现的开销为2到19倍。
{"title":"LVI: Hijacking Transient Execution through Microarchitectural Load Value Injection","authors":"Jo Van Bulck, D. Moghimi, Michael Schwarz, Moritz Lipp, Marina Minkin, Daniel Genkin, Y. Yarom, B. Sunar, D. Gruss, F. Piessens","doi":"10.1109/SP40000.2020.00089","DOIUrl":"https://doi.org/10.1109/SP40000.2020.00089","url":null,"abstract":"The recent Spectre attack first showed how to inject incorrect branch targets into a victim domain by poisoning microarchitectural branch prediction history. In this paper, we generalize injection-based methodologies to the memory hierarchy by directly injecting incorrect, attacker-controlled values into a victim’s transient execution. We propose Load Value Injection (LVI) as an innovative technique to reversely exploit Meltdown-type microarchitectural data leakage. LVI abuses that faulting or assisted loads, executed by a legitimate victim program, may transiently use dummy values or poisoned data from various microarchitectural buffers, before eventually being re-issued by the processor. We show how LVI gadgets allow to expose victim secrets and hijack transient control flow. We practically demonstrate LVI in several proof-of-concept attacks against Intel SGX enclaves, and we discuss implications for traditional user process and kernel isolation. State-of-the-art Meltdown and Spectre defenses, including widespread silicon-level and microcode mitigations, are orthogonal to our novel LVI techniques. LVI drastically widens the spectrum of incorrect transient paths. Fully mitigating our attacks requires serializing the processor pipeline with lfence instructions after possibly every memory load. Additionally and even worse, due to implicit loads, certain instructions have to be blacklisted, including the ubiquitous x86 ret instruction. Intel plans compiler and assembler-based full mitigations that will allow at least SGX enclave programs to remain secure on LVI-vulnerable systems. Depending on the application and optimization strategy, we observe extensive overheads of factor 2 to 19 for prototype implementations of the full mitigation.","PeriodicalId":6849,"journal":{"name":"2020 IEEE Symposium on Security and Privacy (SP)","volume":"81 1","pages":"54-72"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82855953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-05-01DOI: 10.1109/SP40000.2020.00095
Xudong Pan, Mi Zhang, S. Ji, Min Yang
Recently, a new paradigm of building general-purpose language models (e.g., Google’s Bert and OpenAI’s GPT-2) in Natural Language Processing (NLP) for text feature extraction, a standard procedure in NLP systems that converts texts to vectors (i.e., embeddings) for downstream modeling, has arisen and starts to find its application in various downstream NLP tasks and real world systems (e.g., Google’s search engine [6]). To obtain general-purpose text embeddings, these language models have highly complicated architectures with millions of learnable parameters and are usually pretrained on billions of sentences before being utilized. As is widely recognized, such a practice indeed improves the state-of-the-art performance of many downstream NLP tasks. However, the improved utility is not for free. We find the text embeddings from general-purpose language models would capture much sensitive information from the plain text. Once being accessed by the adversary, the embeddings can be reverse-engineered to disclose sensitive information of the victims for further harassment. Although such a privacy risk can impose a real threat to the future leverage of these promising NLP tools, there are neither published attacks nor systematic evaluations by far for the mainstream industry-level language models. To bridge this gap, we present the first systematic study on the privacy risks of 8 state-of-the-art language models with 4 diverse case studies. By constructing 2 novel attack classes, our study demonstrates the aforementioned privacy risks do exist and can impose practical threats to the application of general-purpose language models on sensitive data covering identity, genome, healthcare and location. For example, we show the adversary with nearly no prior knowledge can achieve about 75% accuracy when inferring the precise disease site from Bert embeddings of patients’ medical descriptions. As possible countermeasures, we propose 4 different defenses (via rounding, differential privacy, adversarial training and subspace projection) to obfuscate the unprotected embeddings for mitigation purpose. With extensive evaluations, we also provide a preliminary analysis on the utility-privacy trade-off brought by each defense, which we hope may foster future mitigation researches.
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Pub Date : 2020-05-01DOI: 10.1109/SP40000.2020.00060
Zhenkai Zhang, Zihao Zhan, D. Balasubramanian, B. Li, P. Völgyesi, X. Koutsoukos
The rowhammer bug belongs to software-induced hardware faults, and has been exploited to form a wide range of powerful rowhammer attacks. Yet, how to effectively detect such attacks remains a challenging problem. In this paper, we propose a novel approach named RADAR (Rowhammer Attack Detection via A Radio) that leverages certain electromagnetic (EM) signals to detect rowhammer attacks. In particular, we have found that there are recognizable hammering-correlated sideband patterns in the spectrum of the DRAM clock signal. As such patterns are inevitable physical side effects of hammering the DRAM, they can "expose" any potential rowhammer attacks including the extremely elusive ones hidden inside encrypted and isolated environments like Intel SGX enclaves. However, the patterns of interest may become unapparent due to the common use of spread-spectrum clocking (SSC) in computer systems. We propose a de-spreading method that can reassemble the hammering-correlated sideband patterns scattered by SSC. Using a common classification technique, we can achieve both effective and robust detection-based defense against rowhammer attacks, as evaluated on a RADAR prototype under various scenarios. In addition, our RADAR does not impose any performance overhead on the protected system. There has been little prior work that uses physical side-channel information to perform rowhammer defenses, and to the best of our knowledge, this is the first investigation on leveraging EM side-channel information for this purpose.
该漏洞属于由软件引起的硬件故障，并已被广泛利用，形成了强大的回旋锤攻击。然而，如何有效地检测此类攻击仍然是一个具有挑战性的问题。在本文中，我们提出了一种名为RADAR (Rowhammer Attack Detection via a Radio)的新方法，该方法利用某些电磁(EM)信号来检测Rowhammer攻击。特别是，我们发现在DRAM时钟信号的频谱中存在可识别的锤击相关边带模式。由于这种模式是敲打DRAM的不可避免的物理副作用，它们可以“暴露”任何潜在的rowhammer攻击，包括隐藏在加密和隔离环境(如英特尔SGX飞地)中的极其难以捉摸的攻击。然而，由于在计算机系统中普遍使用扩频时钟(SSC)，感兴趣的模式可能变得不明显。我们提出了一种去扩频的方法，可以重组被SSC散射的锤击相关边带模式。使用一种通用的分类技术，我们可以实现有效和稳健的基于检测的防御，以抵御滚锤攻击，正如在各种场景下的雷达原型上所评估的那样。此外，我们的RADAR不会对受保护系统施加任何性能开销。之前很少有研究使用物理侧信道信息来执行锤防御，据我们所知，这是第一次利用EM侧信道信息来实现这一目的。
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