Toward Black-Box Detection of Logic Flaws in Web Applications

Abstract—Web applications play a very important role in many critical areas, including online banking, health care, and personal communication. This, combined with the limited security training of many web developers, makes web applications one of the most common targets for attackers. In the past, researchers have proposed a large number of white- and black-box techniques to test web applications for the presence of several classes of vulnerabilities. However, traditional approaches focus mostly on the detection of input validation flaws, such as SQL injection and cross-site scripting. Unfortunately, logic vulnerabilities specific to particular applications remain outside the scope of most of the existing tools and still need to be discovered by manual inspection. In this paper we propose a novel black-box technique to detect logic vulnerabilities in web applications. Our approach is based on the automatic identification of a number of behavioral patterns starting from few network traces in which users interact with a certain application. Based on the extracted model, we then generate targeted test cases following a number of common attack scenarios. We applied our prototype to seven real world E-commerce web applications, discovering ten very severe and previously-unknown logic vulnerabilities. I

Lom: discovering logic flaws within MongoDB-based web applications

Logic flaws within web applications will allow malicious operations to be triggered towards back-end database. Existing approaches to identifying logic flaws of database accesses are strongly tied to structured query language (SQL) statement construction and cannot be applied to the new generation of web applications that use not only structured query language (NoSQL) databases as the storage tier. In this paper, we present Lom, a black-box approach for discovering many categories of logic flaws within MongoDBbased web applications. Our approach introduces a MongoDB operation model to support new features of MongoDB and models the application logic as a mealy finite state machine. During the testing phase, test inputs which emulate state violation attacks are constructed for identifying logic flaws at each application state. We apply Lom to several MongoDB-based web applications and demonstrate its effectiveness

Survey on detecting and preventing web application broken access control attacks

Web applications are an essential component of the current wide range of digital services proposition including financial and governmental services as well as social networking and communications. Broken access control vulnerabilities pose a huge risk to that echo system because they allow the attacker to circumvent the allocated permissions and rights and perform actions that he is not authorized to perform. This paper gives a broad survey of the current research progress on approaches used to detect access control vulnerabilities exploitations and attacks in web application components. It categorizes these approaches based on their key techniques and compares the different detection methods in addition to evaluating their strengths and weaknesses. We also spotted and elaborated on some exciting research gaps found in the current literature, Finally, the paper summarizes the general detection approaches and suggests potential research directions for the future

Do not trust me: Using malicious IdPs for analyzing and attacking Single Sign-On

Single Sign-On (SSO) systems simplify login procedures by using an an Identity Provider (IdP) to issue authentication tokens which can be consumed by Service Providers (SPs). Traditionally, IdPs are modeled as trusted third parties. This is reasonable for SSO systems like Kerberos, MS Passport and SAML, where each SP explicitely specifies which IdP he trusts. However, in open systems like OpenID and OpenID Connect, each user may set up his own IdP, and a discovery phase is added to the protocol flow. Thus it is easy for an attacker to set up its own IdP. In this paper we use a novel approach for analyzing SSO authentication schemes by introducing a malicious IdP. With this approach we evaluate one of the most popular and widely deployed SSO protocols - OpenID. We found four novel attack classes on OpenID, which were not covered by previous research, and show their applicability to real-life implementations. As a result, we were able to compromise 11 out of 16 existing OpenID implementations like Sourceforge, Drupal and ownCloud. We automated discovery of these attacks in a open source tool OpenID Attacker, which additionally allows fine-granular testing of all parameters in OpenID implementations. Our research helps to better understand the message flow in the OpenID protocol, trust assumptions in the different components of the system, and implementation issues in OpenID components. It is applicable to other SSO systems like OpenID Connect and SAML. All OpenID implementations have been informed about their vulnerabilities and we supported them in fixing the issues

Automated Dynamic Firmware Analysis at Scale: A Case Study on Embedded Web Interfaces

Embedded devices are becoming more widespread, interconnected, and web-enabled than ever. However, recent studies showed that these devices are far from being secure. Moreover, many embedded systems rely on web interfaces for user interaction or administration. Unfortunately, web security is known to be difficult, and therefore the web interfaces of embedded systems represent a considerable attack surface. In this paper, we present the first fully automated framework that applies dynamic firmware analysis techniques to achieve, in a scalable manner, automated vulnerability discovery within embedded firmware images. We apply our framework to study the security of embedded web interfaces running in Commercial Off-The-Shelf (COTS) embedded devices, such as routers, DSL/cable modems, VoIP phones, IP/CCTV cameras. We introduce a methodology and implement a scalable framework for discovery of vulnerabilities in embedded web interfaces regardless of the vendor, device, or architecture. To achieve this goal, our framework performs full system emulation to achieve the execution of firmware images in a software-only environment, i.e., without involving any physical embedded devices. Then, we analyze the web interfaces within the firmware using both static and dynamic tools. We also present some interesting case-studies, and discuss the main challenges associated with the dynamic analysis of firmware images and their web interfaces and network services. The observations we make in this paper shed light on an important aspect of embedded devices which was not previously studied at a large scale. We validate our framework by testing it on 1925 firmware images from 54 different vendors. We discover important vulnerabilities in 185 firmware images, affecting nearly a quarter of vendors in our dataset. These experimental results demonstrate the effectiveness of our approach

A Course Module On Application Logic Flaws

Software security is extremely important, and even thoroughly tested code may still have exploitable vulnerabilities. Some of these vulnerabilities are caused by logic flaws. Due to the nature of application or business logic, few automated tools can test for these types of security issues. Therefore, it is important for students to learn how to reduce the number of logic flaws when developing software, and how to test for them manually. A course module with a case study was created to teach students about this topic. Case-based teaching methods are used because it allows students to better apply learned skills to real world industrial settings, and there is a lack of case studies available for current software engineering curriculum. The course module includes an introduction, a quiz on the reading, an animated PowerPoint about the case, and a set of discussion questions. The introduction covers what logic flaws are, reducing logic flaws during software development, and how to test for them manually. The case is about eCommerce merchant software Bigcommerce using PayPal Express to collect payment. A flaw lets attackers complete an expensive order using the payment intended for a cheaper order. An animation was created to trace the HTTP interactions and back-end code representing the steps of the exploit from this case, and explain the manual testing method used to discover the exploit. A set of discussion questions has students apply this method to similar code, to find potential vulnerabilities and then fix them. This course module was taught in COMP 727 Secure Software Engineering at North Carolina A&T State University in the Spring 2015 semester. A pre-survey and post-survey on the learning objectives shows students felt they improved their knowledge and skills relating to application logic flaws. A quiz based on the reading shows students understood the material. The quality of student discussions was very high. Discussion question results were graded using a rubric, and three-quarters of the class received an 85% grade or higher. Overall, this case study was effective at teaching students about application logic flaws. It will be made available to other universities, and can be easily integrated into existing curriculum

Advanced Automated Web Application Vulnerability Analysis

Web applications are an integral part of our lives and culture. We useweb applications to manage our bank accounts, interact with friends,and file our taxes. A single vulnerability in one of these webapplications could allow a malicious hacker to steal your money, toimpersonate you on Facebook, or to access sensitive information, suchas tax returns. It is vital that we develop new approaches to discoverand fix these vulnerabilities before the cybercriminals exploit them.In this dissertation, I will present my research on securing the webagainst current threats and future threats. First, I will discuss mywork on improving black-box vulnerability scanners, which are toolsthat can automatically discover vulnerabilities in web applications.Then, I will describe a new type of web application vulnerability:Execution After Redirect, or EAR, and an approach to automaticallydetect EARs in web applications. Finally, I will present deDacota, afirst step in the direction of making web applications secure byconstruction