Biblio

Filters: Author is William Enck  [Clear All Filters]
2022-07-01
Samin Yaseer Mahmud, William Enck.  2022.  Study of Security Weaknesses in Android Payment Service Provider SDKs. Proceedings of the Symposium and Bootcamp on the Science of Security (HotSoS) Poster Session.

Payment Service Providers (PSP) enable application developers to effortlessly integrate complex payment processing code using software development toolkits (SDKs). While providing SDKs reduces the risk of application developers introducing payment vulnerabilities, vulnerabilities in the SDKs themselves can impact thousands of applications. In this work, we propose a static analysis tool for assessing PSP SDKs using OWASP’s MASVS industry standard for mobile application security. A key challenge for the work was reapplying both the MASVS and program analysis tools designed to analyze whole applications to study only a specific SDK. Our preliminary findings show that a number of payment processing libraries fail to meet MASVS security requirements, with evidence of persisting sensitive data insecurely, using outdated cryptography, and improperly configuring TLS. As such, our investigation demonstrates the value of applying security analysis at SDK granularity to prevent widespread deployment of vulnerable code.

2022-09-28
Samin Yaseer Mahmud, K. Virgil English, Seaver Thorn, William Enck, Adam Oest, Muhammad Saad.  2022.  Analysis of Payment Service Provider SDKs in Android. Annual Computer Security Applications Conference (ACSAC).

Payment Service Providers (PSPs) provide software development toolkits (SDKs) for integrating complex payment processing code into applications. Security weaknesses in payment SDKs can impact thousands of applications. In this work, we propose AARDroid for statically assessing payment SDKs against OWASP’s MASVS industry standard for mobile application security. In creating AARDroid, we adapted application-level requirements and program analysis tools for SDK-specific analysis, tailoring dataflow analysis for SDKs using domain-specific ontologies to infer the security semantics of application programming interfaces (APIs). We apply AARDroid to 50 payment SDKs and discover security weaknesses including saving unencrypted credit card information to files, use of insecure cryptographic primitives, insecure input methods for credit card information, and insecure use of WebViews. These results demonstrate the value of applying security analysis at the SDK granularity to prevent the widespread deployment of insecure code.

2017-07-18
Benjamin Andow, Akhil Acharya, Dengfeng Li, University of Illinois at Urbana-Champaign, William Enck, Kapil Singh, Tao Xie, University of Illinois at Urbana-Champaign.  2017.  UiRef: Analysis of Sensitive User Inputs in Android Applications. 10th ACM Conference on Security and Privacy in Wireless and Mobile Networks (WiSec 2017).

Mobile applications frequently request sensitive data. While prior work has focused on analyzing sensitive-data uses originating from well-dened API calls in the system, the security and privacy implications of inputs requested via application user interfaces have been widely unexplored. In this paper, our goal is to understand the broad implications of such requests in terms of the type of sensitive data being requested by applications.

To this end, we propose UiRef (User Input REsolution Framework), an automated approach for resolving the semantics of user inputs requested by mobile applications. UiRef’s design includes a number of novel techniques for extracting and resolving user interface labels and addressing ambiguity in semantics, resulting in signicant improvements over prior work.We apply UiRef to 50,162 Android applications from Google Play and use outlier analysis to triage applications with questionable input requests. We identify concerning developer practices, including insecure exposure of account passwords and non-consensual input disclosures to third parties. These ndings demonstrate the importance of user-input semantics when protecting end users.

2017-03-31
Rui Shu, Xiaohui Gu, William Enck.  2017.  A Study of Security Vulnerabilities on Docker Hub. Proceedings of the ACM Conference on Data and Application Security and Privacy (CODASPY).

Docker containers have recently become a popular approach to provision multiple applications over shared physical hosts in a more lightweight fashion than traditional virtual machines. This popularity has led to the creation of the Docker Hub registry, which distributes a large number of official and community images. In this paper, we study the state of security vulnerabilities in Docker Hub images. We create a scalable Docker image vulnerability analysis (DIVA) framework that automatically discovers, downloads, and analyzes both official and community images on Docker Hub. Using our framework, we have studied 356,218 images and made the following findings: (1) both official and community images contain more than 180 vulnerabilities on average when considering all versions; (2) many images have not been updated for hundreds of days; and (3) vulnerabilities commonly propagate from parent images to child images. These findings demonstrate a strong need for more automated and systematic methods of applying security updates to Docker images and our current Docker image analysis framework provides a good foundation for such automatic security update.

2017-01-03
Rui Shu, Xiaohui Gu, William Enck.  2017.  A Study of Security Vulnerabilities on Docker Hub. Proceedings of the ACM Conference on Data and Application Security and Privacy (CODASPY).
2016-06-23
Adwait Nadkarni, Benjamin Andow, William Enck, Somesh Jha.  2016.  Practical DIFC Enforcement on Android. USENIX Security Symposium.

Smartphone users often use private and enterprise data with untrusted third party applications.  The fundamental lack of secrecy guarantees in smartphone OSes, such as Android, exposes this data to the risk of unauthorized exfiltration.  A natural solution is the integration of secrecy guarantees into the OS.  In this paper, we describe the challenges for decentralized information flow control (DIFC) enforcement on Android.  We propose context-sensitive DIFC enforcement via lazy polyinstantiation and practical and secure network export through domain declassification.  Our DIFC system, Weir, is backwards compatible by design, and incurs less than 4 ms overhead for component startup.  With Weir,  we demonstrate practical and secure DIFC enforcement on Android.

2016-09-29
Rui Shu, Peipei Wang, Sigmund A. Gorski III, Benjamin Andow, Adwait Nadkarni, Luke Deshotels, Jason Gionta, William Enck, Xiaohui Gu.  2016.  A Study of Security Isolation Techniques. ACM Computing Surveys (CSUR).

Security isolation is a foundation of computing systems that enables resilience to different forms of attacks. This article seeks to understand existing security isolation techniques by systematically classifying different approaches and analyzing their properties. We provide a hierarchical classification structure for grouping different security  isolation techniques.  At the top level, we consider two principal aspects: mechanism and policy. Each aspect is broken down into salient dimensions that describe key properties. We break the mechanism into two dimensions: enforcement location and isolation granularity, and break the policy aspect  down into three dimensions: policy generation, policy configurability, and policy lifetime. We apply our classification to a set of representative papers that cover a breadth of security isolation techniques and discuss trade-offs among different design choices and limitations of existing  approaches.