XML Signature Wrapping Still Considered Harmful: A Case Study on the Personal Health Record in Germany

TL;DR

This paper examines the persistent threat of XML Signature Wrapping in web services, using a German Personal Health Record system as a case study, and proposes guidelines for improved XML signature security.

Contribution

It provides a current case study on XSW vulnerabilities and introduces practical guidelines for more secure XML signature processing in SOAP-based web services.

Findings

Identified deficiencies in defending against XSW attacks

Developed a guideline for secure XML signature processing

Highlighted the ongoing relevance of XSW threats

Abstract

XML Signature Wrapping (XSW) has been a relevant threat to web services for 15 years until today. Using the Personal Health Record (PHR), which is currently under development in Germany, we investigate a current SOAP-based web services system as a case study. In doing so, we highlight several deficiencies in defending against XSW. Using this real-world contemporary example as motivation, we introduce a guideline for more secure XML signature processing that provides practitioners with easier access to the effective countermeasures identified in the current state of research.