Michael Philip McIntosh

XML signature element wrapping attacks and countermeasures

Naive use of XML Signature may result in signed documents remainingvulnerable to undetected modification by an adversary. In thetypical usage of XML Signature to protect SOAP messages, anadversary may be capable of modifying valid messages in order togain unauthorized access to protected resources.This paperdescribes the general vulnerability and several related exploits,and proposes appropriate countermeasures. While the attacksdescribed herein may se obvious to security experts once they areexplained, effective countermeasures require careful securitypolicy specification and correct implentation by signed messageproviders and consumers. Since these implenters are not alwayssecurity experts, this paper provides the guidance necessary toprevent these attacks.

Business-driven application security: from modeling to managing secure applications

Business-driven development and management of secure applications and solutions is emerging as a key requirement in the realization of an on demand enterprise. In a given enterprise, individuals acting in various roles contribute to the modeling, development, deployment, and management of the security aspects of a business application. We look at the business-application life cycle and propose a policy-driven approach overlaid on a model-driven paradigm for addressing security requirements. Our approach suggests that security policies are to be modeled using policies and rule templates associated with business processes and models, designed and implemented through infrastructure-managed or application-managed environments based on modeled artifacts, deployed into an infrastructure and potentially customized to meet the security requirements of the consumer, and monitored and managed to reflect a consistent set of policies across the enterprise and all layers of its application infrastructure. We use a pragmatic approach to identify intersection points between the platform-independent modeling of security policies and their concrete articulation and enforcement. This approach offers a way to manage and monitor systems behavior for adherence and compliance to policies. Monitoring may be enabled through both information technology (IT) and business dashboards. Systematic approaches to connect business artifacts to implementation artifacts help implement business policies in system implementations. Best practices and security usage patterns influence the design of reusable and customizable templates. Because interoperability and portability are important in service-oriented architecture (SOA) environments, we list enhancements to standards (e.g., Business Process Execution Language [BPEL], Unified Modeling LanguageTM [UML®]) that must be addressed to achieve an effective life cycle.