Biblio

Cryptography and encryption is a topic that is blurred by its complexity making it difficult for the majority of the public to easily grasp. The focus of our research is based on SSL technology involving CAs, a centralized system that manages and issues certificates to web servers and computers for validation of identity. We first explain how the certificate provides a secure connection creating a trust between two parties looking to communicate with one another over the internet. Then the paper goes into what happens when trust is compromised and how information that is being transmitted could possibly go into the hands of the wrong person. We are proposing a browser plugin, Certificate Authority Rescue Engine (CAre), to serve as an added source of security with simplicity and visibility. In order to see why CAre will be an added benefit to average and technical users of the internet, one must understand what website security entails. Therefore, this paper will dive deep into website security through the use of public key infrastructure and its core components; certificates, certificate authorities, and their relationship with web browsers.

In recent years, with the advances in JavaScript engines and the adoption of HTML5 APIs, web applications begin to show a tendency to shift their functionality from the server side towards the client side, resulting in dense and complex interactions with HTML documents using the Document Object Model (DOM). As a consequence, client-side vulnerabilities become more and more prevalent. In this paper, we focus on DOM-sourced Cross-site Scripting (XSS), which is a kind of severe but not well-studied vulnerability appearing in browser extensions. Comparing with conventional DOM-based XSS, a new attack surface is introduced by DOM-sourced XSS where the DOM could become a vulnerable source as well besides common sources such as URLs and form inputs. To discover such vulnerability, we propose a detecting framework employing hybrid analysis with two phases. The first phase is the lightweight static analysis consisting of a text filter and an abstract syntax tree parser, which produces potential vulnerable candidates. The second phase is the dynamic symbolic execution with an additional component named shadow DOM, generating a document as a proof-of-concept exploit. In our large-scale real-world experiment, 58 previously unknown DOM-sourced XSS vulnerabilities were discovered in user scripts of the popular browser extension Greasemonkey.

The Dark Web is known as the part of the Internet operated by decentralized and anonymous-preserving protocols like Tor. To date, the research community has focused on understanding the size and characteristics of the Dark Web and the services and goods that are offered in its underground markets. However, little is still known about the attacks landscape in the Dark Web. For the traditional Web, it is now well understood how websites are exploited, as well as the important role played by Google Dorks and automated attack bots to form some sort of "background attack noise" to which public websites are exposed. This paper tries to understand if these basic concepts and components have a parallel in the Dark Web. In particular, by deploying a high interaction honeypot in the Tor network for a period of seven months, we conducted a measurement study of the type of attacks and of the attackers behavior that affect this still relatively unknown corner of the Web.

Web applications are the core enabler for most Internet services today. Their standard interfaces allow them to be composed together in different ways in order to support different service workflows. While the modular composition of applications has considerably simplified the provisioning of new Internet services, it has also added new security challenges; the impact of a security breach propagating through the chain far beyond the vulnerable application. To secure web applications, two distinct approaches have been commonly used in the literature. First, white-box approaches leverage the source code in order to detect and fix unintended flaws. Although they cover well the intrinsic flaws within each application, they can barely leverage logic flaws that arise when connecting multiple applications within the same service. On the other hand, black-box approaches analyze the workflow of a service through a set of user interactions, while assuming only little information about its embedded applications. These approaches may have a better coverage, but suffer from a high false positives rate. So far, to the best of our knowledge, there is not yet a single solution that combines both approaches into a common framework. In this paper, we present a new grey-box approach that leverages the advantages of both white-box and black-box. The core component of our system is a semi-supervised learning framework that first learns the nominal behavior of the service using a set of elementary user interactions, and then prune this nominal behavior from attacks that may have occurred during the learning phase. To do so, we leverage a graph-based representation of known attack scenarios that is built using a white-box approach. We demonstrate in this paper the use of our system through a practical use case, including real world attack scenarios that we were able to detect and qualify using our approach.

Cross site scripting (XSS) is a kind of common attack nowadays. The attack patterns with the new technical like HTML5 that makes detection task getting harder and harder. In this paper, we focus on the browser detection mechanism integrated with HTML5 and CORS properties to detect XSS attacks with the rule based filter by using browser extensions. Further, we also present a model of composition pattern estimation system which can be used to judge whether the intercepted request has malicious attempts or not. The experimental results show that our approach can reach high detection rate by tuning our system through some frequently used attack sentences and testing it with the popular tool-kits: XSSer developed by OWASP.

Cross Site Scripting (XSS) and clickjacking have been ranked among the top web application threats in recent times. This paper introduces XBuster - our client-side defence against XSS, implemented as an extension to the Mozilla Firefox browser. XBuster splits each HTTP request parameter into HTML and JavaScript contexts and stores them separately. It searches for both contexts in the HTTP response and handles each context type differently. It defends against all XSS attack vectors including partial script injection, attribute injection and HTML injection. Also, existing XSS filters may inadvertently disable frame busting code used in web pages as a defence against clickjacking. However, XBuster has been designed to detect and neutralize such attempts.

Software development and web applications have become fundamental in our lives. Millions of users access these applications to communicate, obtain information and perform transactions. However, these users are exposed to many risks; commonly due to the developer's lack of experience in security protocols. Although there are many researches about web security and hacking protection, there are plenty of vulnerable websites. This article focuses in analyzing 3 main hacking techniques: XSS, CSRF, and SQL Injection over a representative group of Colombian websites. Our goal is to obtain information about how Colombian companies and organizations give (or not) relevance to security; and how the final user could be affected.

SQL injection is one of the major threats to the security of the web applications. Attackers try to gain unauthorized access to the database, which has vital and private information of the users. Many researchers have provided various techniques and practices to protect the web applications from attackers. There is a plethora of techniques available to perform SQL injection and usually not everyone is familiar with every attack. Hence, this kind of attack is still the most prevalent. In this paper, we have presented the types of SQL injections attacks and most dominant ways to prevent them.

The World Wide Web has become the most common platform for building applications and delivering content. Yet despite years of research, the web continues to face severe security challenges related to data integrity and confidentiality. Rather than continuing the exploit-and-patch cycle, we propose addressing these challenges at an architectural level, by supplementing the web's existing connection-based and server-based security models with a new approach: content-based security. With this approach, content is directly signed and encrypted at rest, enabling it to be delivered via any path and then validated by the browser. We explore how this new architectural approach can be applied to the web and analyze its security benefits. We then discuss a broad research agenda to realize this vision and the challenges that must be overcome.

The World Wide Web has become the most common platform for building applications and delivering content. Yet despite years of research, the web continues to face severe security challenges related to data integrity and confidentiality. Rather than continuing the exploit-and-patch cycle, we propose addressing these challenges at an architectural level, by supplementing the web's existing connection-based and server-based security models with a new approach: content-based security. With this approach, content is directly signed and encrypted at rest, enabling it to be delivered via any path and then validated by the browser. We explore how this new architectural approach can be applied to the web and analyze its security benefits. We then discuss a broad research agenda to realize this vision and the challenges that must be overcome.

Object Injection Vulnerability (OIV) is an emerging threat for web applications. It involves accepting external inputs during deserialization operation and use the inputs for sensitive operations such as file access, modification, and deletion. The challenge is the automation of the detection process. When the application size is large, it becomes hard to perform traditional approaches such as data flow analysis. Recent approaches fall short of narrowing down the list of source files to aid developers in discovering OIV and the flexibility to check for the presence of OIV through various known APIs. In this work, we address these limitations by exploring a concept borrowed from the information retrieval domain called Latent Semantic Indexing (LSI) to discover OIV. The approach analyzes application source code and builds an initial term document matrix which is then transformed systematically using singular value decomposition to reduce the search space. The approach identifies a small set of documents (source files) that are likely responsible for OIVs. We apply the LSI concept to three open source PHP applications that have been reported to contain OIVs. Our initial evaluation results suggest that the proposed LSI-based approach can identify OIVs and identify new vulnerabilities.

We tackle the problem of automated exploit generation for web applications. In this regard, we present an approach that significantly improves the state-of-art in web injection vulnerability identification and exploit generation. Our approach for exploit generation tackles various challenges associated with typical web application characteristics: their multi-module nature, interposed user input, and multi-tier architectures using a database backend. Our approach develops precise models of application workflows, database schemas, and native functions to achieve high quality exploit generation. We implemented our approach in a tool called Chainsaw. Chainsaw was used to analyze 9 open source applications and generated over 199 first- and second-order injection exploits combined, significantly outperforming several related approaches.

Recent incidents have once again brought the topic of encryption to public discourse, while researchers continue to demonstrate attacks that highlight the difficulty of implementing encryption even without the presence of "backdoors". However, apart from the threat of implementation flaws in encryption libraries, another significant threat arises when web services fail to enforce ubiquitous encryption. A recent study explored this phenomenon in popular services, and demonstrated how users are exposed to cookie hijacking attacks with severe privacy implications. Many security mechanisms purport to eliminate this problem, ranging from server-controlled options such as HSTS to user-controlled options such as HTTPS Everywhere and other browser extensions. In this paper, we create a taxonomy of available mechanisms and evaluate how they perform in practice. We design an automated testing framework for these mechanisms, and evaluate them using a dataset of 30 days of HTTP requests collected from the public wireless network of our university's campus. We find that all mechanisms suffer from implementation flaws or deployment issues and argue that, as long as servers continue to not support ubiquitous encryption across their entire domain (including all subdomains), no mechanism can effectively protect users from cookie hijacking and information leakage.

Web applications must ultimately command systems like web browsers and database engines using strings. Strings derived from improperly sanitized user input can as a result be a vector for command injection attacks. In this paper, we introduce regular string types, which classify strings constrained statically to be in a regular language specified by a regular expression. Regular strings support standard string operations like concatenation and substitution, as well as safe coercions, so they can be used to implement, in an essentially conventional manner, the pieces of a web application or framework that handle strings arising from user input. Simple type annotations at function interfaces can be used to statically verify that sanitization has been performed correctly without introducing redundant run-time checks. We specify this type system first as a minimal typed lambda calculus, lambdaRS. To be practical, adopting a specialized type system like this should not require the adoption of a new programming language. Instead, we advocate for extensible type systems: new type system fragments like this should be implemented as libraries atop a mechanism that guarantees that they can be safely composed. We support this with two contributions. First, we specify a translation from lambdaRS to a calculus with only standard strings and regular expressions. Then, taking Python as a language with these constructs, we implement the type system together with the translation as a library using typy, an extensible static type system for Python.

In many client-facing applications, a vulnerability in any part can compromise the entire application. This paper describes the design and implementation of Passe, a system that protects a data store from unintended data leaks and unauthorized writes even in the face of application compromise. Passe automatically splits (previously shared-memory-space) applications into sandboxed processes. Passe limits communication between those components and the types of accesses each component can make to shared storage, such as a backend database. In order to limit components to their least privilege, Passe uses dynamic analysis on developer-supplied end-to-end test cases to learn data and control-flow relationships between database queries and previous query results, and it then strongly enforces those relationships. Our prototype of Passe acts as a drop-in replacement for the Django web framework. By running eleven unmodified, off-the-shelf applications in Passe, we demonstrate its ability to provide strong security guarantees-Passe correctly enforced 96% of the applications' policies-with little additional overhead. Additionally, in the web-specific setting of the prototype, we also mitigate the cross-component effects of cross-site scripting (XSS) attacks by combining browser HTML5 sandboxing techniques with our automatic component separation.

In an attempt to support customization, many web applications allow the integration of third-party server-side plugins that offer diverse functionality, but also open an additional door for security vulnerabilities. In this paper we study the use of static code analysis tools to detect vulnerabilities in the plugins of the web application. The goal is twofold: 1) to study the effectiveness of static analysis on the detection of web application plugin vulnerabilities, and 2) to understand the potential impact of those plugins in the security of the core web application. We use two static code analyzers to evaluate a large number of plugins for a widely used Content Manage-ment System. Results show that many plugins that are current-ly deployed worldwide have dangerous Cross Site Scripting and SQL Injection vulnerabilities that can be easily exploited, and that even widely used static analysis tools may present disappointing vulnerability coverage and false positive rates.