214 research outputs found

    Quantifying the security risk of discovering and exploiting software vulnerabilities

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    2016 Summer.Includes bibliographical references.Most of the attacks on computer systems and networks are enabled by vulnerabilities in a software. Assessing the security risk associated with those vulnerabilities is important. Risk mod- els such as the Common Vulnerability Scoring System (CVSS), Open Web Application Security Project (OWASP) and Common Weakness Scoring System (CWSS) have been used to qualitatively assess the security risk presented by a vulnerability. CVSS metrics are the de facto standard and its metrics need to be independently evaluated. In this dissertation, we propose using a quantitative approach that uses an actual data, mathematical and statistical modeling, data analysis, and measurement. We have introduced a novel vulnerability discovery model, Folded model, that estimates the risk of vulnerability discovery based on the number of residual vulnerabilities in a given software. In addition to estimating the risk of vulnerabilities discovery of a whole system, this dissertation has furthermore introduced a novel metrics termed time to vulnerability discovery to assess the risk of an individual vulnerability discovery. We also have proposed a novel vulnerability exploitability risk measure termed Structural Severity. It is based on software properties, namely attack entry points, vulnerability location, the presence of the dangerous system calls, and reachability analysis. In addition to measurement, this dissertation has also proposed predicting vulnerability exploitability risk using internal software metrics. We have also proposed two approaches for evaluating CVSS Base metrics. Using the availability of exploits, we first have evaluated the performance of the CVSS Exploitability factor and have compared its performance to Microsoft (MS) rating system. The results showed that exploitability metrics of CVSS and MS have a high false positive rate. This finding has motivated us to conduct further investigation. To that end, we have introduced vulnerability reward programs (VRPs) as a novel ground truth to evaluate the CVSS Base scores. The results show that the notable lack of exploits for high severity vulnerabilities may be the result of prioritized fixing of vulnerabilities

    Herding Vulnerable Cats: A Statistical Approach to Disentangle Joint Responsibility for Web Security in Shared Hosting

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    Hosting providers play a key role in fighting web compromise, but their ability to prevent abuse is constrained by the security practices of their own customers. {\em Shared} hosting, offers a unique perspective since customers operate under restricted privileges and providers retain more control over configurations. We present the first empirical analysis of the distribution of web security features and software patching practices in shared hosting providers, the influence of providers on these security practices, and their impact on web compromise rates. We construct provider-level features on the global market for shared hosting -- containing 1,259 providers -- by gathering indicators from 442,684 domains. Exploratory factor analysis of 15 indicators identifies four main latent factors that capture security efforts: content security, webmaster security, web infrastructure security and web application security. We confirm, via a fixed-effect regression model, that providers exert significant influence over the latter two factors, which are both related to the software stack in their hosting environment. Finally, by means of GLM regression analysis of these factors on phishing and malware abuse, we show that the four security and software patching factors explain between 10\% and 19\% of the variance in abuse at providers, after controlling for size. For web-application security for instance, we found that when a provider moves from the bottom 10\% to the best-performing 10\%, it would experience 4 times fewer phishing incidents. We show that providers have influence over patch levels--even higher in the stack, where CMSes can run as client-side software--and that this influence is tied to a substantial reduction in abuse levels

    Assessing The Security Posture Of Openemr Using Capec Attack Patterns

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    Attack patterns describe the common methods of exploiting software. Good software engineering practices and principles alone are not enough to produce secure software. It is also important to know how software it attacked and to guard against it. Knowledge of attack patterns provides a good perspective of an attacker, thus enabling developers and testers to build secure software. CAPEC list is a taxonomy of attack patterns which we believe can enhance security testing. This research seeks to assess the security posture of OpenEMR 4.1.1, an open source Electronic Medical Record (EMR) system, based on CAPEC attack patterns. Five categories of CAPEC attack patterns were analyzed to find their relevance and applicability to OpenEMR. Whereas inapplicable attack patterns were not further considered, applicable attack patterns were further tested to assess OpenEMR vulnerability to them. Various security testing tools were used to carry out the tests. Attack patterns helped to focus black-box and white-box testing procedures on what and where to test. OpenEMR was found to be vulnerable to a number of vulnerabilities such as cross site scripting, authentication bypass, session sidejacking, among others. A number of exploitations were carried out based on the vulnerabilities discovered

    Vulnerability discovery in multiple version software systems: open source and commercial software systems

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    Department Head: L. Darrell Whitley.2007 Summer.Includes bibliographical references (pages 80-83).The vulnerability discovery process for a program describes the rate at which the vulnerabilities are discovered. A model of the discovery process can be used to estimate the number of vulnerabilities likely to be discovered in the near future. Past studies have considered vulnerability discovery only for individual software versions, without considering the impact of shared code among successive versions and the evolution of source code. These affecting factors in vulnerability discovery process need to be taken into account estimate the future software vulnerability discovery trend more accurately. This thesis examines possible approaches for taking these factors into account in the previous works. We implemented these factors on vulnerability discovery process. We examine a new approach for quantitatively vulnerability discovery process, based on shared source code measurements among multiple version software system. The applicability of the approach is examined using Apache HTTP Web server and Mysql DataBase Management System (DBMS). The result of this approach shows better goodness of fit than fitting result in the previous researches. Using this revised software vulnerability discovery process, the superposition effect which is an unexpected vulnerability discovery in the previous researches could be determined by software discovery model. The multiple software vulnerability discovery model (MVDM) shows that vulnerability discovery rate is different with single vulnerability discovery model's (SVDM) discovery rate because of newly considered factors. From these result, we create and applied new SVDM for open source and commercial software. This single vulnerability process is examined, and the model testing result shows that SVDM can be an alternative modeling. The modified vulnerability discovery model will be presented for supporting previous researches' weakness, and the theoretical modeling will be discuss for more accurate explanation

    Real-time fusion and projection of network intrusion activity

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    Intrusion Detection Systems (IDS) warn of suspicious or malicious network activity and are a fundamental, yet passive, defense-in-depth layer for modern networks. Prior research has applied information fusion techniques to correlate the alerts of multiple IDSs and group those belonging to the same multi-stage attack into attack tracks. Projecting the next likely step in these tracks potentially enhances an analyst’s situational awareness; however, the reliance on attack plans, complicated algorithms, or expert knowledge of the respective network is prohibitive and prone to obsolescence with the continual deployment of new technology and evolution of hacker tradecraft. This thesis presents a real-time continually learning system capable of projecting attack tracks that does not require a priori knowledge about network architecture or rely on static attack templates. Prediction correctness over time and other metrics are used to assess the system’s performance. The system demonstrates the successful real-time adaptation of the model, including enhancements such as the prediction that a never before observed event is about to occur. The intrusion projection system is framed as part of a larger information fusion and impact assessment architecture for cyber security
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