ISM-1439

If using CDNs, disclosing the IP addresses of web servers under an organisation’s control (referred to as origin servers) is avoided and access to the origin servers is restricted to the CDNs and authorised management networks.

Topic
Using content delivery networks
Applicable to
all

History

Priority
should
Mar 2022
If using CDNs, disclosing the IP addresses of web servers under an organisation’s control (referred to as origin servers) is avoided and access to the origin servers is restricted to the CDNs and authorised management networks.
Miscellaneous changes were made to rationale and recommendations throughout the publication to clarify content without changing intent. This included a review from the Guidelines for System Hardening chapter through to the Guidelines for Data Transfers chapter.
Dec 2021
If using a CDN, disclosing the IP address of the web server under the organisation’s control (referred to as the origin server) is avoided and access to the origin server is restricted to the CDN and an authorised management network.
Miscellaneous changes were made to rationale and security controls throughout the publication. This included:
• A review from the Using the Information Security Manual chapter through to the Guidelines for Media chapter.
• Security controls suitable for all audiences have been identified with the ‘All’ applicability marking while additional security controls suitable for just government audiences have been identified with the O, P, S and TS applicability markings.
• Security controls suitable for specific classifications have been amended to include their classification(s) in the wording of the security controls to reduce the reliance on applicability markings to confer suitability.
• Tables in security controls have been converted into prose to allow for inclusion in the SSP annex template and the XML list of security controls.
• The use of ‘official’ and ‘highly classified’ terminology has been replaced with specific classifications to remove ambiguity.
• Security controls relating to high assurance ICT equipment have had their applicability narrowed to ‘S, TS’ reflecting that they are intended for the protection of SECRET and TOP SECRET systems and data.
2015
If using a content delivery network, disclosing the IP address of the web server under theagency’s control (referred to as the origin server) should be avoided.