The application must ensure each unique asserting party provides unique assertion ID references for each SAML assertion.

From Application Security and Development Security Technical Implementation Guide

Associated with: CCI-000068

SV-83905r2_rule The application must ensure each unique asserting party provides unique assertion ID references for each SAML assertion.

Vulnerability discussion

SAML is a standard for exchanging authentication and authorization data between security domains. SAML uses security tokens containing assertions to pass information about a principal (usually an end user) between a SAML authority, (identity provider), and a SAML consumer, (service provider). SAML assertions are usually made about a subject, (user) represented by the <Subject> element. SAML assertion identifiers should be unique across a system implementation. Duplicate SAML assertion identifiers could lead to unauthorized access to a web service.

Check content

Ask the application representative for the design document. Review the design document for web services using SAML assertions. If the application does not utilize SAML assertions, this check is not applicable. Review the design document and verify SAML assertion identifiers are not reused by a single asserting party. If the design document does not exist, or does not indicate SAML assertion identifiers which are unique for each asserting party, this is a finding.

Fix text

Design and configure each SAML assertion authority to use unique assertion identifiers.

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