The web server must disable HTTP/1.x downgrading.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-264363 | SRG-APP-000439-WSR-000193 | SV-264363r984434_rule | CCI-002418 | medium |
| Description | ||||
| HTTP/2 is backward compatible with HTTP/1.x, so it is possible to configure the architecture to implement a front-end server for HTTP/2 while communicating with one or more back-end servers that support only HTTP/1.x. Thus, the front end effectively has to translate or downgrade the requests it receives into the less secure protocol. HTTP downgrading negates the benefits of HTTP/2. If HTTP downgrading cannot be avoided, validate the rewritten/downgraded request against the HTTP/1.1 specification. For example, reject requests that contain newlines in the headers, colons in header names, and spaces in the request method. | ||||
| STIG | Date | |||
| Web Server Security Requirements Guide | 2025-02-12 | |||
Details
Check Text (C-264363r984434_chk)
If HTTP downgrading is operationally necessary, and the rewritten request is validated against HTTP/1.x specification (i.e., verify requests that contain new lines in the headers, colons in header names, and spaces in the request method are rejected), mark as a CAT III finding.
Verify that HTTP/1.x downgrading is disabled.
If the HTTP/1.x downgrading is enabled, this is a finding.
Fix Text (F-68184r984433_fix)
Configure the web server to disable HTTP/1.x downgrading.
If HTTP downgrading is operationally necessary, validate the rewritten request against the HTTP/1.1 specification, i.e., reject requests that contain new lines in the headers, colons in header names, and spaces in the request method.