241 research outputs found
The Android Platform Security Model
Android is the most widely deployed end-user focused operating system. With
its growing set of use cases encompassing communication, navigation, media
consumption, entertainment, finance, health, and access to sensors, actuators,
cameras, or microphones, its underlying security model needs to address a host
of practical threats in a wide variety of scenarios while being useful to
non-security experts. The model needs to strike a difficult balance between
security, privacy, and usability for end users, assurances for app developers,
and system performance under tight hardware constraints. While many of the
underlying design principles have implicitly informed the overall system
architecture, access control mechanisms, and mitigation techniques, the Android
security model has previously not been formally published. This paper aims to
both document the abstract model and discuss its implications. Based on a
definition of the threat model and Android ecosystem context in which it
operates, we analyze how the different security measures in past and current
Android implementations work together to mitigate these threats. There are some
special cases in applying the security model, and we discuss such deliberate
deviations from the abstract model
CamFlow: Managed Data-sharing for Cloud Services
A model of cloud services is emerging whereby a few trusted providers manage
the underlying hardware and communications whereas many companies build on this
infrastructure to offer higher level, cloud-hosted PaaS services and/or SaaS
applications. From the start, strong isolation between cloud tenants was seen
to be of paramount importance, provided first by virtual machines (VM) and
later by containers, which share the operating system (OS) kernel. Increasingly
it is the case that applications also require facilities to effect isolation
and protection of data managed by those applications. They also require
flexible data sharing with other applications, often across the traditional
cloud-isolation boundaries; for example, when government provides many related
services for its citizens on a common platform. Similar considerations apply to
the end-users of applications. But in particular, the incorporation of cloud
services within `Internet of Things' architectures is driving the requirements
for both protection and cross-application data sharing.
These concerns relate to the management of data. Traditional access control
is application and principal/role specific, applied at policy enforcement
points, after which there is no subsequent control over where data flows; a
crucial issue once data has left its owner's control by cloud-hosted
applications and within cloud-services. Information Flow Control (IFC), in
addition, offers system-wide, end-to-end, flow control based on the properties
of the data. We discuss the potential of cloud-deployed IFC for enforcing
owners' dataflow policy with regard to protection and sharing, as well as
safeguarding against malicious or buggy software. In addition, the audit log
associated with IFC provides transparency, giving configurable system-wide
visibility over data flows. [...]Comment: 14 pages, 8 figure
Mitigating Docker Security Issues
It is very easy to run applications in Docker. Docker offers an ecosystem
that offers a platform for application packaging, distributing and managing
within containers. However, Docker platform is yet not matured. Presently,
Docker is less secured as compare to virtual machines (VM) and most of the
other cloud technologies. The key of reason of Docker inadequate security
protocols is containers sharing of Linux kernel, which can lead to risk of
privileged escalations. This research is going to outline some major security
vulnerabilities at Docker and counter solutions to neutralize such attacks.
There are variety of security attacks like insider and outsider. This research
will outline both types of attacks and their mitigations strategies. Taking
some precautionary measures can save from huge disasters. This research will
also present Docker secure deployment guidelines. These guidelines will suggest
different configurations to deploy Docker containers in a more secure way.Comment: 11 page
Beyond SELinux: the Case for Behavior-Based Policy and Trust Languages
Despite the availability of powerful mechanisms for security policy and access control, real-world information security practitioners---both developers and security officers---still find themselves in need of something more. We believe that this is the case because available policy languages do not provide clear and intelligible ways to allow developers to communicate their knowledge and expectations of trustworthy behaviors and actual application requirements to IT administrators. We work to address this policy engineering gap by shifting the focus of policy language design to this communication via behavior-based policies and their motivating scenarios
Functionality-based application confinement: A parameterised and hierarchical approach to policy abstraction for rule-based application-oriented access controls
Access controls are traditionally designed to protect resources from users, and consequently make access decisions based on the identity of the user, treating all processes as if they are acting on behalf of the user that runs them. However, this user-oriented approach is insufficient at protecting against contemporary threats, where security compromises are often due to applications running malicious code, either due to software vulnerabilities or malware. Application-oriented access controls can mitigate this threat by managing the authority of individual applications. Rule-based application-oriented access controls can restrict applications to only allow access to the specific finely-grained resources required for them to carry out their tasks, and thus can significantly limit the damage that can be caused by malicious code. Unfortunately existing application-oriented access controls have policy complexity and usability problems that have limited their use.
This thesis proposes a new access control model, known as functionality-based application confinement (FBAC). The FBAC model has a number of unique features designed to overcome problems with previous approaches. Policy abstractions, known as functionalities, are used to assign authority to applications based on the features they provide. Functionalities authorise elaborate sets of finely grained privileges based on high-level security goals, and adapt to the needs of specific applications through parameterisation. FBAC is hierarchical, which enables it to provide layers of abstraction and encapsulation in policy. It also simultaneously enforces the security goals of both users and administrators by providing discretionary and mandatory controls.
An LSM-based (Linux security module) prototype implementation, known as FBAC-LSM, was developed as a proof-of-concept and was used to evaluate the new model and associated techniques. The policy requirements of over one hundred applications were analysed, and policy abstractions and application policies were developed. Analysis showed that the FBAC model is capable of representing the privilege needs of applications. The model is also well suited to automaiii tion techniques that can in many cases create complete application policies a priori, that is, without first running the applications. This is an improvement over previous approaches that typically rely on learning modes to generate policies. A usability study was conducted, which showed that compared to two widely-deployed alternatives (SELinux and AppArmor), FBAC-LSM had significantly higher perceived usability and resulted in significantly more protective policies. Qualitative analysis was performed and gave further insight into the issues surrounding the usability of application-oriented access controls, and confirmed the success of the FBAC model
Clustering and recommendation techniques for access control policy management
Managing access control policies can be a daunting process, given the frequent policy decisions that need to be made, and the potentially large number of policy rules involved. Policy management includes, but is not limited to: policy optimization, configuration, and analysis. Such tasks require a deep understanding of the policy and its building compo- nents, especially in scenarios where it frequently changes and needs to adapt to different environments. Assisting both administrators and users in performing these tasks is impor- tant in avoiding policy misconfigurations and ill-informed policy decisions. We investigate a number of clustering and recommendation techniques, and implement a set of tools that assist administrators and users in managing their policies. First, we propose and imple- ment an optimization technique, based on policy clustering and adaptable rule ranking, to achieve optimal request evaluation performance. Second, we implement a policy analysis framework that simplifies and visualizes analysis results, based on a hierarchical cluster- ing algorithm. The framework utilizes a similarity-based model that provides a basis of risk analysis on newly introduced policy rules. In addition to administrators, we focus on regular individuals whom nowadays manage their own access control polices on a regular basis. Users are making frequent policy decisions, especially with the increasing popular- ity of social network sites, such as Facebook and Twitter. For example, users are required to allow/deny access to their private data on social sites each time they install a 3rd party application. To make matters worse, 3rd party access requests are mostly uncustomizable by the user. We propose a framework that allows users to customize their policy decisions
on social sites, and provides a set of recommendations that assist users in making well- informed decisions. Finally, as the browser has become the main medium for the users online presence, we investigate the access control models for 3rd party browser extensions. Even though, extensions enrich the browsing experience of users, they could potentially represent a threat to their privacy. We propose and implement a framework that 1) monitors 3rd party extension accesses, 2) provides fine-grained permission controls, and 3) Provides detailed permission information to users in effort to increase their privacy aware- ness. To evaluate the framework we conducted a within-subjects user study and found the framework to effectively increase user awareness of requested permissions
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