NIST 800-53 REV 5 • SYSTEM AND COMMUNICATIONS PROTECTION
SC-7(8) — Route Traffic to Authenticated Proxy Servers
Route {{ insert: param, sc-07.08_odp.01 }} to {{ insert: param, sc-07.08_odp.02 }} through authenticated proxy servers at managed interfaces.
CMMC Practice Mapping
No direct CMMC mapping
NIST 800-171 Mapping
No direct NIST 800-171 mapping
Related Controls
Supplemental Guidance
External networks are networks outside of organizational control. A proxy server is a server (i.e., system or application) that acts as an intermediary for clients requesting system resources from non-organizational or other organizational servers. System resources that may be requested include files, connections, web pages, or services. Client requests established through a connection to a proxy server are assessed to manage complexity and provide additional protection by limiting direct connectivity. Web content filtering devices are one of the most common proxy servers that provide access to the Internet. Proxy servers can support the logging of Transmission Control Protocol sessions and the blocking of specific Uniform Resource Locators, Internet Protocol addresses, and domain names. Web proxies can be configured with organization-defined lists of authorized and unauthorized websites. Note that proxy servers may inhibit the use of virtual private networks (VPNs) and create the potential for "man-in-the-middle" attacks (depending on the implementation).
Practitioner Notes
Outbound web traffic from your users should route through an authenticated proxy server that can inspect, filter, and log the traffic before it reaches the internet.
Example 1: Deploy a web proxy (Zscaler, Squid, or Blue Coat) that requires user authentication before allowing internet access. The proxy logs every URL visited, blocks known malicious sites, and prevents access to unauthorized categories like file sharing or anonymizers.
Example 2: Configure a GPO to set the proxy server address on all domain-joined workstations and prevent users from changing proxy settings. Use WPAD or PAC files to route traffic through the proxy automatically. The proxy authenticates users via Kerberos against Active Directory.