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.