ATTACKS AND COUNTERMEASURES FOR WEBVIEW ON MOBILE SYSTEMS

ABSTRACT All the mainstream mobile operating systems provide a web container, called ``WebView\u27\u27. This Web-based interface can be included as part of the mobile application to retrieve and display web contents from remote servers. WebView not only provides the same functionalities as web browser, more importantly, it enables rich interactions between mobile apps and webpages loaded inside WebView. Through its APIs, WebView enables the two-way interaction. However, the design of WebView changes the landscape of the Web, especially from the security perspective. This dissertation conducts a comprehensive and systematic study of WebView\u27s impact on web security, with a particular focus on identifying its fundamental causes. This dissertation discovers multiple attacks on WebView, and proposes new protection models to enhance the security of WebView. The design principles of these models are also described as well as the prototype implementation in Android platform. Evaluations are used to demonstrate the effectiveness and performance of these protection models

Mediums: Visual integrity preserving framework

The UI redressing attack and its variations have spread across several platforms, from web browsers to mobile systems. We study the fundamental problem underneath such attacks, and formulate a generic model called the containerthreat model. We believe that the attacks are caused by the system’s failure to preserve visual integrity. From this angle, we study the existing countermeasures and propose a generic approach, Mediums framework, to develop a Trusted DisplayBase (TDB) to address this type of problems. We use the side channel to convey the lost visual information to users. From the access control perspective, we use the dynamic binding policy model to allow the server to enforce different restrictions based on different client-side scenarios

Fine-Grained Access Control for HTML5-Based Mobile Applications in Android

HTML5-based mobile applications are becoming more and more popular because they can run on different platforms. Several newly introduced mobile OS natively support HTML5-based applications. For those that do not provide native sup-port, such as Android, iOS, and Windows Phone, developers can develop HTML5-based applications using middlewares, such as PhoneGap [17]. In these platforms, programs are loaded into a web component, called WebView, which can render HTML5 pages and execute JavaScript code. In order for the program to access the system resources, which are isolated from the content inside WebView due to its sand-box, bridges need to be built between JavaScript and the native code (e.g. Java code in Android). Unfortunately, such bridges break the existing protection that was origi-nally built into WebView. In this paper, we study the potential risks of HTML5-based applications, and investigate how the existing mobile systems ’ access control supports these applications. We fo-cus on Android and the PhoneGap middleware. However, our ideas can be applied to other platforms. Our studies indicate that Android does not provide an adequate access control for this kind of applications. We propose a fine-grained access control mechanism for the bridge in Android system. We have implemented our scheme in Android and have evaluated its effectiveness and performance. 1

Code Injection Attacks on HTML5-based Mobile Apps

HTML5-based mobile apps become more and more popular, mostly because they are much easier to be ported across different mobile platforms than native apps. HTML5-based apps are implemented using the standard web technologies, including HTML5, JavaScript and CSS; they depend on some middlewares, such as PhoneGap, to interact with the underlying OS. Knowing that JavaScript is subject to code injection attacks, we have conducted a systematic study on HTML5-based mobile apps, trying to evaluate whether it is safe to rely on the web technologies for mobile app development. Our discoveries are quite surprising. We found out that if HTML5-based mobile apps become popular--it seems to go that direction based on the current projection--many of the things that we normally do today may become dangerous, including reading from 2D barcodes, scanning Wi-Fi access points, playing MP4 videos, pairing with Bluetooth devices, etc. This paper describes how HTML5-based apps can become vulnerable, how attackers can exploit their vulnerabilities through a variety of channels, and what damage can be achieved by the attackers. In addition to demonstrating the attacks through example apps, we have studied 186 PhoneGap plugins, used by apps to achieve a variety of functionalities, and we found that 11 are vulnerable. We also found two real HTML5-based apps that are vulnerable to the attacks.Comment: In Proceedings of the Third Workshop on Mobile Security Technologies (MoST) 2014 (http://arxiv.org/abs/1410.6674

Attacks on WebView in the Android System

WebView is an essential component in both Android and iOS platforms, enabling smartphone and tablet apps to embed a simple but powerful browser inside them. To achieve a better interaction between apps and their embedded\browsers , WebView provides a number of APIs, allowing code in apps to invoke and be invoked by the JavaScript code within the web pages, intercept their events, and modify those events. Using these features, apps can become customized \browsers for their intended web applications. Currently, in the Android market, 86 percent of the top 20 most downloaded apps in 10 diverse categories use WebView. The design ofWebView changes the landscape of theWeb, especially from the security perspective. Two essential pieces of the Web\u27s security infrastructure are weakened if Web- View and its APIs are used: the Trusted Computing Base (TCB) at the client side, and the sandbox protection implemented by browsers. As results, many attacks can be launched either against apps or by them. The objective of this paper is to present these attacks, analyze their fundamental causes, and discuss potential solutions

Mediums: Visual Integrity Preserving Framework ∗

The UI redressing attack and its variations have spread across several platforms, from web browsers to mobile systems. We study the fundamental problem underneath such attacks, and formulate a generic model called the container threat model. We believe that the attacks are caused by the system’s failure to preserve visual integrity. From this angle, we studytheexistingcountermeasuresandpropose ageneric approach, Mediumsframework, todevelopaTrusted Display Base (TDB) to address this type of problems. We use the side channel to convey the lost visual information to users. From the access control perspective, we use the dynamic binding policy model to allow the server to enforce different restrictions based on different client-side scenarios

Scuta: A server-side access control system for web applications

The Web is playing a very important role in our lives, and is becoming an essential element of the computing infrastructure. Unfortunately, its importance makes it the preferred target of attacks. Web-based vulnerabilities now outnumber traditional computer security concerns. A recent study shows that over 80 percent of web sites have had at least one serious vulnerability. We believe that the Web’s problems, to a large degree, are caused by the inadequacy of its underlying access control systems. To reduce the number of vulnerabilities, it is essential to provide web applications with better access control models that can adequately address the protection needs of the current Web. As a part of the efforts to develop a better access control system for the Web, we focus on the server-side access control in this paper. We introduce a new concept called subsession, based on which, we have developed a ringbased access control system (called Scuta) for web servers. Scuta provides a fine-grained and backward-compatible access control mechanism for web applications. We have implemented Scuta in PHP, and have conducted comprehensive case studies to evaluate its benefits