CVE-2019-9628 in XMLTooling
Summary
by MITRE
The XMLTooling library all versions prior to V3.0.4, provided with the OpenSAML and Shibboleth Service Provider software, contains an XML parsing class. Invalid data in the XML declaration causes an exception of a type that was not handled properly in the parser class and propagates an unexpected exception type.
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Analysis
by VulDB Data Team • 08/01/2023
The vulnerability identified as CVE-2019-9628 resides within the XMLTooling library, a critical component of the OpenSAML and Shibboleth Service Provider software ecosystems. This library serves as the foundational XML processing mechanism for handling security tokens and assertions in identity federation scenarios, making it a prime target for attackers seeking to disrupt authentication services. The flaw manifests in the XML parsing class where malformed data within XML declarations triggers unhandled exception propagation, creating a potential denial of service condition that could compromise the availability of authentication services.
The technical root cause of this vulnerability stems from improper exception handling within the XML parsing implementation. When the parser encounters invalid data in XML declarations, it throws an exception that does not conform to the expected exception types handled by the application logic. This mismatch in exception handling creates a scenario where the system cannot gracefully process malformed input, leading to abrupt termination of processing threads or application crashes. The vulnerability specifically affects all versions prior to V3.0.4 of the XMLTooling library, indicating that the developers identified and corrected this issue through improved exception management protocols. This flaw aligns with CWE-704, which addresses improper exception handling, and represents a classic example of how inadequate error management can create security weaknesses in parsing components.
The operational impact of CVE-2019-9628 extends beyond simple service disruption to potentially enable more sophisticated attack vectors within identity federation environments. Attackers could exploit this vulnerability to perform denial of service attacks against Shibboleth Service Providers or OpenSAML implementations, causing authentication services to become unavailable to legitimate users. In identity federation contexts, where these systems handle critical authentication flows for enterprise networks, academic institutions, and government agencies, such disruptions could cascade into broader security incidents. The vulnerability particularly affects systems that process external XML inputs without proper sanitization, making it relevant to the ATT&CK technique of Service Stoppage under the Execution tactic.
Organizations utilizing affected versions of OpenSAML or Shibboleth Service Provider software should prioritize immediate remediation through the upgrade to XMLTooling V3.0.4 or later versions. Additionally, system administrators should implement input validation mechanisms to filter malformed XML content before it reaches the vulnerable parsing components. Network segmentation and monitoring solutions should be deployed to detect unusual patterns of XML processing failures that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper exception handling in security-sensitive components, particularly those involved in identity management and authentication processes where reliability directly impacts overall system security posture.