The ALG providing user authentication intermediary services using PKI-based user authentication must implement a local cache of revocation data to support path discovery and validation in case of the inability to access revocation information via the network.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-54529	SRG-NET-000345-ALG-000099	SV-68775r1_rule		Medium

Description
Without configuring a local cache of revocation data, there is the potential to allow access to users who are no longer authorized (users with revoked certificates). The intent of this requirement is to require support for a secondary certificate validation method using a locally cached revocation data, such as Certificate Revocation List (CRL), in case access to OCSP (required by CCI-000185) is not available. Based on a risk assessment, an alternate mitigation is to configure the system to deny access when revocation data is unavailable. This requirement applies to ALGs that provide user authentication intermediary services (e.g., authentication gateway or TLS gateway). This does not apply to authentication for the purpose of configuring the device itself (device management).

Description

Without configuring a local cache of revocation data, there is the potential to allow access to users who are no longer authorized (users with revoked certificates). The intent of this requirement is to require support for a secondary certificate validation method using a locally cached revocation data, such as Certificate Revocation List (CRL), in case access to OCSP (required by CCI-000185) is not available. Based on a risk assessment, an alternate mitigation is to configure the system to deny access when revocation data is unavailable. This requirement applies to ALGs that provide user authentication intermediary services (e.g., authentication gateway or TLS gateway). This does not apply to authentication for the purpose of configuring the device itself (device management).

STIG	Date
Application Layer Gateway Security Requirements Guide	2014-11-03

Details

Check Text ( C-55145r2_chk )
If the ALG does not provide PKI-based user authentication intermediary services, this is not applicable. Verify the ALG implements a local cache of revocation data to support path discovery and validation in case of the inability to access revocation information via the network. If the ALG does not implement a local cache of revocation data to support path discovery and validation in case of the inability to access revocation information via the network, this is a finding.

Check Text ( C-55145r2_chk )

If the ALG does not provide PKI-based user authentication intermediary services, this is not applicable.

Verify the ALG implements a local cache of revocation data to support path discovery and validation in case of the inability to access revocation information via the network.

If the ALG does not implement a local cache of revocation data to support path discovery and validation in case of the inability to access revocation information via the network, this is a finding.

Fix Text (F-59383r2_fix)
If PKI-based user authentication intermediary services are provided, configure the ALG to implement a local cache of revocation data to support path discovery and validation in case of the inability to access revocation information via the network.