Biblio

Many web applications are vulnerable to Cross Site Scripting (XSS) attacks enabling attackers to steal sensitive information and commit frauds. Much research in this area have focused on detecting vulnerable web pages using static and dynamic program analysis. The best practice to prevent XSS vulnerabilities is to encode untrusted dynamic content. However, a common programming error is the use of a wrong type of encoder to sanitize untrusted data, leaving the application vulnerable. We propose a new approach that can automatically fix this common type of XSS vulnerability in many situations. This approach is integrated into the software maintenance life cycle through unit testing. Vulnerable codes are refactored to reflect the suggested encoder and then verified using an attack evaluating mechanism to find a proper repair. Evaluation of this approach has been conducted on an open source medical record application with over 200 web pages written in JSP.

The best practice to prevent Cross Site Scripting (XSS) attacks is to apply encoders to sanitize untrusted data. To balance security and functionality, encoders should be applied to match the web page context, such as HTML body, JavaScript, and style sheets. A common programming error is the use of a wrong encoder to sanitize untrusted data, leaving the application vulnerable. We present a security unit testing approach to detect XSS vulnerabilities caused by improper encoding of untrusted data. Unit tests for the XSS vulnerability are automatically constructed out of each web page and then evaluated by a unit test execution framework. A grammar-based attack generator is used to automatically generate test inputs. We evaluate our approach on a large open source medical records application, demonstrating that we can detect many 0-day XSS vulnerabilities with very low false positives, and that the grammar-based attack generator has better test coverage than industry best practices.

Integrating security testing into the workflow of software developers not only can save resources for separate security testing but also reduce the cost of fixing security vulnerabilities by detecting them early in the development cycle. We present an automatic testing approach to detect a common type of Cross Site Scripting (XSS) vulnerability caused by improper encoding of untrusted data. We automatically extract encoding functions used in a web application to sanitize untrusted inputs and then evaluate their effectiveness by automatically generating XSS attack strings. Our evaluations show that this technique can detect 0-day XSS vulnerabilities that cannot be found by static analysis tools. We will also show that our approach can efficiently cover a common type of XSS vulnerability. This approach can be generalized to test for input validation against other types injections such as command line injection.

Code coverage is a widely used measure to determine how thoroughly an application is tested. There are many tools available for different languages. However, to the best of our knowledge, most of them focus on unit testing and ignore end-to-end tests with ui- or web tests. Furthermore, there is no support for determining code coverage of transcompiled cross-platform applications. This kind of application is written in one language, but compiled to and executed in a different programming language. Besides, it may run on a different platform. In this paper, we propose a new code coverage testing method that calculates the code coverage of any kind of test (unit-, integration- or ui-/web-test) for any type of (transcompiled) applications (desktop, web or mobile application). Developers obtain information about which parts of the source code are uncovered by tests. The basis of our approach is generic and may be applied in numerous programming languages based on an abstract syntax tree. We present our approach for any-kind-applications developed in Java and evaluate our tool on a web application created with Google Web Toolkit, on standard desktop applications, and on some small Java applications that use the Swing library to create user interfaces. Our results show that our tool is able to judge the code coverage of any kind of test. In particular, our tool is independent of the unit- or ui-/web test-framework in use. The runtime performance is promising although it is not as fast as already existing tools in the area of unit-testing.