Title

The application must use the NotOnOrAfter condition when using the SubjectConfirmation element in a SAML assertion. (Cat I impact)

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. When a SAML assertion is used with a <SubjectConfirmation> element, a begin and end time for the <SubjectConfirmation> should be set to prevent reuse of the message at a later time. Not setting a specific time period for the <SubjectConfirmation>, may grant immediate access to an attacker and result in an immediate loss of confidentiality.

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. Examine the contents of a SOAP message using the <SubjectConfirmation> element. All messages should contain the <NotOnOrAfter> element. This can be accomplished if the application allows the ability to view XML messages or via a protocol analyzer like Wireshark. If SOAP messages do not contain <NotOnOrAfter> elements, this is a finding.

Fix Text

Design and configure the application to use the <NotOnOrAfter> condition when using the <SubjectConfirmation> element in a SAML assertion.

Additional Identifiers

Rule ID: SV-222403r879519_rule

Vulnerability ID: V-222403

Group Title: SRG-APP-000014

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.