CVE-2017-16852 in Service Provider
Summary
by MITRE
shibsp/metadata/DynamicMetadataProvider.cpp in the Dynamic MetadataProvider plugin in Shibboleth Service Provider before 2.6.1 fails to properly configure itself with the MetadataFilter plugins and does not perform critical security checks such as signature verification, enforcement of validity periods, and other checks specific to deployments, aka SSPCPP-763.
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Analysis
by VulDB Data Team • 01/10/2023
The vulnerability identified as CVE-2017-16852 resides within the Dynamic MetadataProvider component of the Shibboleth Service Provider software, specifically in the shibsp/metadata/DynamicMetadataProvider.cpp file. This issue affects versions prior to 2.6.1 and represents a critical security flaw that undermines the fundamental integrity of the metadata handling mechanism. The vulnerability stems from improper configuration of the Dynamic MetadataProvider plugin with MetadataFilter plugins, creating a dangerous gap in the security posture of Shibboleth deployments.
The technical flaw manifests as a complete failure to perform essential security validations that are critical for maintaining trust in federated identity systems. The Dynamic MetadataProvider plugin neglects to implement signature verification mechanisms that should validate the authenticity of metadata sources, effectively allowing potentially malicious or unauthorized metadata to be processed without proper authentication. Additionally, the vulnerability disables the enforcement of validity periods, meaning that metadata entries can remain active beyond their intended expiration dates, creating opportunities for stale or compromised metadata to be utilized in authentication processes. This failure to validate deployment-specific security requirements creates multiple attack vectors that could be exploited by adversaries seeking to compromise federated identity environments.
The operational impact of this vulnerability extends far beyond simple functionality degradation, as it fundamentally compromises the security model of Shibboleth Service Provider deployments. Organizations relying on Shibboleth for federated identity management face significant risks including potential identity spoofing attacks, unauthorized access to protected resources, and complete bypass of security controls that should protect against malicious metadata injection. The vulnerability affects the core metadata processing pipeline, meaning that any system utilizing dynamic metadata provisioning becomes susceptible to attacks that could compromise user authentication and authorization flows. This risk is particularly severe in environments where Shibboleth serves as a critical component of identity and access management infrastructure.
Security professionals should recognize this vulnerability as a direct violation of security best practices and standards such as those outlined in CWE-284 for improper access control and CWE-347 for improper certificate validation. The flaw aligns with ATT&CK technique T1552 for credentials from password storage modules, as compromised metadata could lead to unauthorized access to protected systems. Organizations should immediately implement mitigations including upgrading to Shibboleth Service Provider version 2.6.1 or later, which contains the necessary security fixes. Additional defensive measures should include implementing strict metadata source validation, monitoring for unauthorized metadata changes, and ensuring that all metadata processing components are properly configured with appropriate signature verification mechanisms. The vulnerability serves as a stark reminder of the critical importance of proper security validation in identity management systems and the potential consequences when these validations are absent.